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Statins and postoperative risk of atrial fibrillation following coronary artery bypass grafting.

Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting. Atrial remodeling has been observed in AF and has been associated with the development of this arrhythmia. Because 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) have been demonstrated to modify remodeling, we hypothesized a protective role of statins against postoperative AF. We also hypothesized that extracellular matrix turnover and brain natriuretic peptide (BNP) might be related to such atrial remodeling. We studied 234 consecutive patients who underwent coronary artery bypass grafting (173 men; 65 +/- 9 years of age) in whom the occurrence of postoperative AF was monitored. In a subgroup of 66 patients, we measured plasma levels of matrix metalloproteinase-1 (MMP-1), its inhibitor, tissue inhibitor matrix metalloproteinase-1 (TIMP-1; as indexes of extracellular matrix remodeling), and N-terminus pro-BNP (related to left ventricular function) at baseline and at 24 hours after surgery. Of 234 patients, 66 (28.2%) developed postoperative AF. In multivariate analysis, previous AF was related to an increase in the development of AF (odds ratio 11.92, 95% confidence interval 2.37 to 59.98, p = 0.026), whereas statin use was related to a decrease in arrhythmia (odds ratio 0.52, 95% confidence interval 0.28 to 0.96, p = 0.038). A higher TIMP-1/MMP-1 ratio at 24 hours after surgery was present in those who did not develop postoperative AF (p = 0.043). Statin use was associated with increased TIMP-1 levels and TIMP-1/MMP-1 ratio (p = 0.027 and 0.036, respectively). No significant relations to N-terminus pro-BNP were seen. In conclusion, previous AF and nonuse of statins are significantly associated with AF after coronary artery bypass grafting. Statin use may be protective against AF after coronary artery bypass grafting, possibly due to alterations in the extracellular matrix and remodeling after coronary artery bypass grafting.

Left atrial appendage flow velocity as a quantitative surrogate parameter for thromboembolic risk: determinants and relationship to spontaneous echocontrast and thrombus formation--a transesophageal echocardiographic study in 500 patients with cerebral ischemia.

Hemostasis in the left atrial (LA) appendage (LAA) is an important cause in the formation of thrombi. Determination of the LAA flow velocity (LAAV) could be a quantitative parameter for estimating thromboembolic risk. The objective of this study was to: (1) determine the relationship between LAAV and qualitative parameters with elevated thromboembolic risk (thrombus/spontaneous echocontrast [SEC]); and (2) define factors that influence LAAV.</AbstractText>In all, 500 patients with stroke were examined consecutively by transesophageal echocardiography. In addition to measurement of the LAAV, the atrial appendage was examined for the presence of thrombi or SEC.</AbstractText>LAAV differed significantly among patients with sinus rhythm (71 +/- 16 cm/s), paroxysmal atrial fibrillation (AF) and in sinus rhythm during transesophageal echocardiography (46 +/- 13 cm/s), paroxysmal AF and AF during transesophageal echocardiography (32 +/- 12 cm/s), and chronic AF (27 +/- 9 cm/s, P &lt; .001). Independent of the rhythm, the risk of thrombus/SEC increased significantly at an LAAV less than 55 cm/s. At an LAAV 55 cm/s or more there is only a minimal risk of thrombus/SEC (negative predictive value 100% and 99%, respectively). Multivariate analysis showed that LAAV is the strongest predictor for the occurrence of thrombus/SEC (P &lt; .0001). Further multivariate analysis showed that left ventricular ejection fraction, LA size, (paroxysmal) AF, age, and sex are independent parameters influencing LAAV.</AbstractText>Independent of the basic rhythm, there is a close relationship between LAAV and qualitative parameters of elevated thromboembolic risk. LAAV could, therefore, be a quantitative surrogate parameter for risk stratification. It is influenced by both cardiac and extracardiac factors.</AbstractText>

Exercise intolerance in patients with atrial fibrillation: clinical and echocardiographic determinants of exercise capacity.

Although exercise intolerance is a major symptom of patients with atrial fibrillation (AF), the factors limiting these patients' exercise capacity remains uncertain. This study evaluated the correlation of clinical and echocardiographic parameters with exercise capacity of patients with AF. In all, 73 patients (61 men and 12 women; mean age 61 years) with chronic AF were included in this study. Those patients with primary valvular diseases were excluded. Standard 2-dimensional and Doppler echocardiography was performed, and we averaged 10 consecutive measurements of each variable. Patients then underwent a symptom-limited treadmill exercise testing. We also measured patients' plasma levels of B-type natriuretic peptide before exercise testing. Of all clinical and echocardiographic parameters we assessed, age (r = -0.45, P = .006), ratio of early mitral inflow velocity to mitral annular velocity (r = -0.35, P = .032), and baseline heart rate were independent predictors of exercise capacity on multivariate regression analysis. In conclusion, patient's age, averaged ratio of early mitral inflow velocity to mitral annular velocity, and baseline heart rate provided useful information on exercise intolerance for patients with AF. Ratio of early mitral inflow velocity to mitral annular velocity, a noninvasive tool for estimating left ventricular filling pressure, may especially have important value for predicting functional capacity in this population as it has in individuals with in sinus rhythm.

Doppler tissue imaging and color M-mode flow propagation velocity: are they really preload independent?

This study investigated the change in new diastolic indexes in patients with uremia who undergo regular hemodialysis (H/D).</AbstractText>We studied 81 patients with uremia (41 men and 40 women) receiving regular H/D. All patients were in sinus rhythm before H/D. They had normal left ventricular systolic performance without regional wall-motion abnormality. Three patients were excluded because of atrial fibrillation after H/D. Patients were separated by the amount of body fluid removed during H/D procedure: 30 patients with H/D amount less than 2 kg (group 1), 33 patients with H/D amount between 2 and 3 kg (group 2), and 18 patients with H/D amount larger than 3 kg (group 3). They received complete transthoracic echocardiographic examinations. Flow propagation velocity (FPV) was measured by color M-mode echocardiography in apical 4-chamber view. Mitral annulus Doppler tissue velocities (peak systolic [Sa], early diastolic [Ea], and late diastolic [Aa]) were measured from septal, lateral, inferior, and posterior walls. All these parameters were obtained immediately before and after H/D. Paired data were compared.</AbstractText>In patients with removed fluid amount less than 2 kg (group 1), the change of all diastolic parameters showed insignificant change except FPV (peak mitral E, P = .14; peak mitral A, P = .916; FPV, P = .009; septal Sa, P = .173; septal Ea, P = .295; septal Aa, P = .649). In patients with H/D amount between 2 and 3 kg, the change of all diastolic parameters showed statistically significant difference except Sa (peak mitral E, P = .001; peak mitral A, P = .001; FPV, P = .001; Sa, P = .589; Ea, P = .001; Aa, P = .015). In patients with H/D amount larger than 3 kg, Sa still showed insignificant change. Ea, Aa, and FPV showed significant difference after H/D (peak mitral E, P = .001; peak mitral A, P = .035; FPV, P = .008; septal Sa, P = .777; septal Ea, P = .014; septal Aa, P = .048).</AbstractText>In patients with normal left ventricular systolic function, FPV was preload dependent. Diastolic phase mitral annulus Doppler tissue velocities (Ea and Aa) behaved differently according to the amount removed during H/D. They were preload independent when the amount removed during H/D was less than 2 kg. When the amount removed during H/D was larger than 2 kg, diastolic phase mitral annulus Doppler tissue velocities changed significantly. That is to say, diastolic phase mitral annulus Doppler tissue velocities were not totally preload independent. For systolic phase mitral annulus Doppler tissue velocity index (Sa), it was preload independent.</AbstractText>

Autologous myoblast transplantation after myocardial infarction increases the inducibility of ventricular arrhythmias.

Small scale clinical trials suggested the feasibility and the efficacy of autologous myoblast transplantation to improve ventricular function after myocardial infarction. However, these trials were hampered by unexpected episodes of life-threatening ventricular tachyarrhythmias (VT). We investigated cardiac electrical stability after myoblast transplantation to the myocardium.</AbstractText>Seven days after coronary ligation, Wistar rats were randomized into 3 groups: a control group receiving no further treatment, a vehicle group injected with culture medium into the infarcted myocardium, and a myoblast group injected with autologous myoblasts. Holter monitoring did not discriminate the myoblast from the vehicle groups. Programmed Electrical Stimulation (PES) was performed to evaluate further a cardiac substrate for arrhythmia susceptibility. The occurrence of sustained VT during PES was similar in control and vehicle groups (5/17 and 4/19 rats, respectively; p=0.50). In contrast, 13/20 rats (65%) from the myoblast group showed at least one episode of sustained VT during PES (p&lt;0.05 and p&lt;0.005 versus control and vehicle groups). As a further control group, rats injected with autologous bone marrow mononuclear cells into the infarcted myocardium did not show increased susceptibility to PES.</AbstractText>In an infarcted rat model, myoblast transplantation but not bone marrow mononuclear cells or myocardial injection per se induces electrical ventricular instability. Because ventricular arrhythmias are life-threatening disorders, we suggest that such preclinical evaluation should be conducted for any new source of cells to be injected into the myocardium.</AbstractText>

Current status and future prospects for a vaccine against American trypanosomiasis.

The clinically relevant pathognomonic consequences of human infection by Trypanosoma cruzi are dilation and hypertrophy of the left ventricle walls and thinning of the apex. The major complications and debilitating evolutionary outcomes of chronic infection include ventricular fibrillation, thromboembolism and congestive heart failure. American trypanosomiasis (Chagas disease) poses serious public healthcare and budgetary concerns. The currently available drugs, although effective against acute infection, are highly toxic and ineffective in arresting or attenuating clinical disease symptoms in chronic patients. The development of an efficacious prophylactic vaccine faces many challenges, and progress is slow, despite several years of effort. Studies in animal models and human patients have revealed the pathogenic mechanisms during disease progression, pathology of disease and features of protective immunity. Accordingly, several antigens, antigen-delivery vehicles and adjuvants have been tested in animal models, and some efforts have been successful in controlling infection and disease. This review will summarize the accumulated knowledge about the parasite and disease, as well as pathogenesis and protective immunity. The authors will discuss the efforts to date, and the challenges faced in achieving an efficient prophylactic vaccine against human American trypanosomiasis, and present the future perspectives.

Prodromal angina reduces infarcted mass less in interventionally reperfused than in thrombolysed myocardial infarction.

There is a lot of evidence that angina during the 24-48 h before a reperfused myocardial infarction improves the evolution of the patients. However, there are studies that failed to demonstrate this protective effect of preinfarction angina in an interventional reperfusion setting.</AbstractText>To compare the effect of preinfarction angina (PIA) on inhospital evolution of thrombolysis vs. interventionally reperfused acute myocardial infarction (AMI).</AbstractText>There were prospectively studied 133 consecutive AMI patients, eligible for reperfusion (thrombolysis or interventional). History of PIA under 48 hours was obtained. Evolution of AMI was evaluated considering the following end-points: the ratio between the number of ECG leads with final pathologic Q wave and the number of leads with initial ST elevation, CK-MB values, separate and composite incidence of death, heart failure, shock and incidence of serious arrhythmia (sustained VT or ventricular fibrillation).</AbstractText>ECG ratio was lower in patients with PIA (0.511 +/- 0.281 vs. 0.646 +/- 0.274, p=0.02) in thrombolysed patients, but it was higher in interventionally reperfused patients (0.740 +/- 0.418 vs. 0.554 +/- 0.295 p=0.11). CK-MB values were lowered by PIA in thrombolysed AMI (122 +/- 74 vs. 190 +/- 89, p=0.0003), but they were not in the interventional group. Clinical end-points were slightly less frequent in patients with PIA, in both reperfusion groups, but not statistically significant. Major arrhythmia occurred less frequently in interventionally reperfused patients with PIA (9.5% vs. 31.6%, p=0.12).</AbstractText>Preinfarction angina under 48 hours significantly reduces infarcted mass (measured by ECG and enzymes) in thrombolysed patients, but not in the interventional group. However, PIA reduced arrhythmic end-point in interventional setting.</AbstractText>

[Cardiac arrest caused by an ecstasy intoxication].

We report about a 19 years old man, suffering from an cardiac arrest (ventricular fibrillation) caused by an ecstasy intoxication. A supraventricular tachycardia was recorded on day three after resuscitation. No pathological findings were demonstrated by coronary angiography. An slow- fast- av -nodal- reentry- tachycardia (AVNRT) was detected and successfully treated by electrical ablation of the slow pathway during electrophysiological mapping. No severe neurological deficits were found in discharge from hospital.

[Polytrauma with tension pneumothorax with inserted chest tube].

The authors report a case of a 25-year-old woman with a polytrauma, caused by a free fall of 12 metres in suicidal intention. Following endotracheal intubation and mechanical ventilation by an emergency physician at the scene, the patient was delivered to the emergency room of an university hospital. An ultrasonic check of the abdomen revealed free fluid in the abdominal cavity, and a rupture of liver and spleen was suspected. Since breath sounds over the right lung were diminished, a chest tube was inserted immediately in the fifth intercostal space in the anterior axillary line. About 300 millilitres of blood were drained by the tube. Shortly thereafter, a laparotomy was performed, where spleen and liver rupture were confirmed and treated. After 60 minutes, the patient developed severe hypotension coupled with ventricular tachycardia and fibrillation, and resuscitation measures had to be initiated. Since breath sounds over the right lung were missing, a tension pneumothorax was suspected and a thoracotomy performed immediately. While huge amounts of air and blood were emerging from the thoracic cavity, a rupture of the right mainstem bronchus as well as of the right pulmonary artery and vena subclavia was identified. The chest tube was found dislocated into the subcutaneous tissue. Despite of open heart compression, application of adrenaline and noradrenaline and substitution of packed red blood cells and of crystalloid and colloid solutions, all resuscitation measures failed so that the patient died shortly after on the operation table. This case illustrates first the difficulties of an adequate thoracic trauma management, particularly, when clinical symptoms are discrete, second the problems of the insertion and control of a chest tube, and third risks associated with wrong position or secondary dislocation which may include - as in our case - "masking" of severe injury patterns and delay of life-saving measures such as an immediate thoracotomy. In order to improve prognosis of patients with poly-/thoracic trauma, establishment of spiral-CT in emergency centres, routine bronchoscopy and safe handling of chest tubes may be helpful.

B-type natriuretic peptide testing for structural heart disease screening: a general population-based study.

Several types of structural heart disease are important precursors for congestive heart failure or cardioembolic stroke. We have previously demonstrated that plasma B-type natriuretic peptide (BNP) measurement is useful for detection of structural heart disease in a multiphasic health screening setting. To extend our hypothesis to the general population, the utility of BNP testing for identifying structural heart disease was assessed in a general population and in subgroups divided by sex, age, and presence/absence of risk factors.</AbstractText>This cross-sectional cohort study measured plasma BNP concentrations in 993 randomly selected community-dwelling adults (mean age 58 years). All subjects underwent plasma BNP measurement and transthoracic echocardiography. Using prejudged criteria, 41 subjects were diagnosed to have some form of structural heart disease (mild left ventricular systolic dysfunction in 11, valvular heart disease in 9, hypertensive heart disease in 3, hypertrophic cardiomyopathy in 2, ischemic heart disease in 2, lone atrial fibrillation in 14). The utility of BNP testing was evaluated by receiver operating characteristic (ROC) analysis and by cost analysis for detection of 1 case within each subgroup of the cohort. Overall, the sensitivity and specificity of BNP testing for identification of structural heart disease were 61% and 92%, respectively. The area under the ROC curve was 0.77 (95% CI; 0.74-0.79). When sex-specific ROC analyses were performed, sensitivity and specificity were 61% and 91% in men, and 50% and 95% in women, respectively. Although the performance of BNP testing on the basis of these figures might be suboptimal, efficacy was improved in subgroups with a high prevalence of heart disease (&gt;8%) such as the cohort aged &gt; or =65 years (men, area under ROC curve = 0.88; cost &lt;US $1400: women, area under ROC curve = 0.83; cost &lt;US $3000) as well as the cohort having cardiovascular risk factors such as hypertension or diabetes (men, area under ROC curve = 0.85; cost &lt;US $1700: women, area under ROC curve = 0.83; cost &lt;US $3100).</AbstractText>The present results suggest that BNP testing for structural heart disease screening in community-based populations is useful for cohorts with a high prevalence of heart disease. However, its efficacy is reduced in cohorts with a low prevalence rate.</AbstractText>

Ethanol induction of complete heart block in swine.

A method for the induction of complete heart block (CHB) by ethanol injection and its success rate in a pig model of acute right ventricular failure is reported. Additionally, a review of the literature for the induction of CHB in laboratory animals is detailed. The literature review was undertaken to both compare our rate of success with other methods and provide insight into our technique and refine its implementation.</AbstractText>Animal models of CHB have facilitated the understanding of therapeutics for various cardiac pathologies in humans. In our laboratory, CHB in pigs is used for complete control of heart rhythm in studies of biventricular pacing.</AbstractText>Experiments carried out on pigs in our laboratory that required the induction of CHB were reviewed retrospectively. In addition, review of the literature for creating CHB in animals was undertaken. Our success rate was compared to that of other groups.</AbstractText>Our success rate (93%) is similar to other models of CHB, in general, and to those models that used the injection of caustic substances with thoracotomy.</AbstractText>Review of the literature indicates that our success rate is comparable to other groups and that, although many approaches have been described in both open- and closed-chest models, success is likely dependent on the practice and skill of the experimenter. In addition, review of the literature has afforded us new perspectives on the experimental induction of CHB.</AbstractText>

Defibrillation energy requirements using a left anterior chest cutaneous to subcutaneous shocking vector: implications for a total subcutaneous implantable defibrillator.

Subcutaneous implantable defibrillators (ICDs) are being developed to facilitate ICD implantation.</AbstractText>The purpose of this study was to estimate the human defibrillation energy requirement (DER) using a left chest cutaneous (Q) to subcutaneous (SQ) shocking vector.</AbstractText>Twenty patients undergoing implantation of an indicated ICD were enrolled (15 males, age = 63 +/- 12 years; ejection fraction = 0.27 +/- 0.14). Defibrillation testing was performed using an investigational system consisting of an external defibrillator and a constructed connector to deliver a shock between a pectoral SQ can and a cardiac apical Q electrode. Two attempts at defibrillation using this configuration were allowed. Stage 1 testing started at 70 J with a step-down/step-up to 50 or 100 J, respectively. Stage 2 testing began at 50 J with a step-down/step-up to 30 or 70 J.</AbstractText>During stage 1, a 70-J shock was successful in 7/9 (78%) patients. A second attempt was successful in 7/7 patients using a 50-J shock. In the two remaining patients, a second attempt using a 100-J shock was successful. During stage 2, a 50-J shock was successful in 10/11 (91%) patients. The protocol could not be completed in 2/11 patients. Of the remaining nine patients, a second defibrillation was successful in seven (78%) using a 30-J shock.</AbstractText>The defibrillation energy requirement (DER) of this study vector was 50 J or less in most patients. This low DER supports further investigation of a totally SQ-ICD. However, the DER of 100 J in two patients indicates that further investigation is needed regarding DER variability and safety margins.</AbstractText>

Safety and efficacy of radiofrequency energy catheter ablation of atrial fibrillation in patients with pacemakers and implantable cardiac defibrillators.

Catheter ablation has significantly transformed the clinical management of atrial fibrillation (AF). The safety and efficacy of this procedure are not well understood in patients with pacemakers and defibrillators.</AbstractText>The purpose of this study was to study the impact of radiofrequency catheter ablation of AF in patients with pacemakers and implantable cardiac defibrillators.</AbstractText>We studied 86 patients with pacemakers and defibrillators (group I) and a similar number of age- and gender-matched controls (group II) who underwent AF ablation between 1999 and 2004. Clinical and procedural variables were compared between the two groups. In group I, various generator and lead parameters were compared before and after the procedure. Resurgence of clinical AF after 2 months was considered recurrence.</AbstractText>Both groups were similar with regard to age, gender, body mass index, and type of AF. Group I had a higher incidence of diabetes (17% vs 6%, P = .03), coronary artery disease (25% vs 13%, P = .05), less prolonged AF (31 +/- 21 vs 45 +/- 30 months, P &lt;.001), lower left ventricular ejection fraction (49 +/- 13% vs 52 +/- 9%, P = .03), and left ventricular end-diastolic dimensions (4.97 +/- 0.81 vs 4.72 +/- 0.67, P = .03). No changes in the sensing and pacing thresholds, impedance of atrial and ventricular leads, or defibrillator coil impedance after AF ablation were observed in group I. Atrial lead dislodgment was seen in two patients. Transient abnormal but "expected" pulse generator behavior was seen in 25% of patients without permanent malfunction. Stroke (1% vs 1%, P = 1.000), pulmonary vein stenosis (2% vs 1%, P = .77), and AF recurrence rates at 12 months were similar between groups I and II, respectively (19% vs 21%, P = .73).</AbstractText>AF ablation is safe and efficacious in patients with pacemakers and defibrillators.</AbstractText>

Impact of upgrade to cardiac resynchronization therapy on ventricular arrhythmia frequency in patients with implantable cardioverter-defibrillators.

This study compared cardiac resynchronization therapy's (CRT) impact on ventricular tachyarrhythmia susceptibility in patients who, due to worsening heart failure (HF) symptoms, underwent a replacement of a conventional implantable cardioverter-defibrillator (ICD) with a CRT-ICD.</AbstractText>Cardiac resynchronization therapy is an effective addition to conventional treatment of HF in many patients with left ventricular systolic dysfunction. However, whether CRT-induced improvements in HF status also reduce susceptibility to life-threatening arrhythmias is less certain.</AbstractText>Clinical and ICD electrogram data were evaluated in 18 consecutive ICD patients who underwent an upgrade to CRT-ICD. Pharmacologic HF therapy was not altered during follow-up. The definition of ventricular tachycardia (VT) and ventricular fibrillation (VF) for each patient was as determined by device programming. Statistical comparisons used paired t tests.</AbstractText>Findings were recorded during two time periods: 47 +/- 21 months (range 24 to 70 months) before and 14 +/- 2 months (range 9 to 18 months) after CRT upgrade. At time of upgrade, patient age was 69 +/- 11 years and ejection fraction was 21 +/- 8%. Before CRT the frequency of VT, VF, and appropriate ICD shocks was 0.31 +/- 1.23, 0.047 +/- 0.083, and 0.048 +/- 0.085 episodes/month/patient, respectively. After CRT-ICD, VT and VF arrhythmia burdens and frequency of shocks were respectively 0.13 +/- 0.56, 0.001 +/- 0.004, and 0.003 +/- 0.016 episodes/month/patient (p = 0.59, 0.03, and 0.05 vs. pre-CRT).</AbstractText>Arrhythmia frequency and number of appropriate ICD treatments were reduced after upgrade to CRT-ICD for HF treatment. Thus, apart from hemodynamic benefits, CRT may also ameliorate ventricular tachyarrhythmia susceptibility in HF patients.</AbstractText>

Cardiac resynchronization therapy: Part 2--issues during and after device implantation and unresolved questions.

Encouraged by the clinical success of cardiac resynchronization therapy (CRT), the implantation rate has increased exponentially, although several limitations and unresolved issues of CRT have been identified. This review concerns issues that are encountered during implantation of CRT devices, including the role of electroanatomical mapping, whether CRT implantation should be accompanied by simultaneous atrioventricular nodal ablation in patients with atrial fibrillation, procedural complications, and when to consider surgical left ventricular lead positioning. Furthermore, (echocardiographic) CRT optimization and assessment of CRT benefits after implantation are highlighted. Also, controversial issues such as the potential value of CRT in patients with mild heart failure or narrow QRS complex are addressed. Finally, open questions concerning when to combine CRT with implantable cardioverter-defibrillator therapy and the cost-effectiveness of CRT are discussed.

Long-term mortality in patients with pauses in ventricular electrical activity.

The long-term significance of ventricular pauses of &gt; or =3.0 seconds observed on Holter monitor is unclear, as previously conducted retrospective studies have been poorly controlled. We compared the prognosis of patients with pauses &gt; or =3.0 seconds on Holter monitor with a well-matched control group without such pauses.</AbstractText>Scanning the Holter database at Ochsner Clinic (n = 11,730; January 1998 to June 2003) for pauses &gt; or =3.0 seconds identified 70 patients (pause group). Of those, 29 (37.1%) received a permanent pacemaker (PPM group) and 41 (62.9%) did not (No-PPM group). For each No-PPM patient, two patients without pauses (&lt;2.0 seconds) exactly matched for age, sex, ejection fraction (EF), rhythm, and duration of follow-up were randomly chosen from the Holter database (control group, n = 82) and survival of the two groups was compared.</AbstractText>Mean age was 72.5 +/- 15.0 years, mean EF was 52.2 +/- 12.7%, and 68.3% were men. Mean follow-up was 2.2 years (0.5-4.5 years). There was no difference in survival between the No-PPM and the control groups (82.9% vs 84.1%, P = NS). Compared with the PPM group, pauses in the No-PPM group were more commonly asymptomatic, nocturnal, and due to sinus pauses or atrial fibrillation (AF) with slow ventricular response.</AbstractText>Pauses in ventricular electrical activity &gt; or =3 seconds on Holter monitor due to sinus pauses or AF with slow ventricular response are not predictive of heightened mortality.</AbstractText>

The impact of catecholamines on defibrillation threshold in patients with implanted cardioverter defibrillators.

To determine the effect of physiologic catecholamine concentrations on the defibrillation threshold (DFT) in patients with implanted cardioverter defibrillators.</AbstractText>DFT is the minimum energy delivered by an implanted cardioverter defibrillator that successfully converts ventricular fibrillation. DFT testing is performed under conscious sedation. Since activities of daily living enhance sympathetic tone substantially over these nadir levels, it is important to explore the impact of catecholamines on DFT.</AbstractText>In this double-blind study, we determined DFT by the step-down method. Patients (n = 50) were stratified by beta-blocker use and then randomized to a 7-minute infusion of epinephrine, norepinephrine, or placebo. After study infusion, DFT testing was repeated. Changes in DFT with different study medications were compared. Subgroup analyses of the effects of catecholamines on DFT, based on beta-blocker use, were also performed.</AbstractText>Norepinephrine reduced DFT from baseline measurements by 22.6% (P = 0.008). Neither epinephrine nor placebo impacted DFT (P = 0.999, P = 0.317, respectively). In the subgroup analyses, DFT was reduced with norepinephrine regardless of beta-blocker use, while epinephrine reduced DFT among those receiving beta-blockers. No change in DFT was observed in either of the placebo subgroups.</AbstractText>Elevation of plasma norepinephrine concentrations reduces the DFT, while elevations in epinephrine had no effect. Norepinephrine seems to reduce DFT regardless of beta-blocker therapy but epinephrine's effects are beta-blocker dependent.</AbstractText>

Mean frequency of premature ventricular complexes as predictor of malignant ventricular arrhythmias.

The aim was to test the hypothesis that mean frequency of premature ventricular complexes (PVCs) correlates with vulnerability to malignant arrhythmias such as ventricular tachycardia and/or ventricular fibrillation (VT/VF).</AbstractText>Patients with an implantable cardioverter defibrillator (ICD) device for underlying ischemic or non-ischemic cardiac pathology were selected from a database. Availability of total count of single (s) PVCs and runs (r) of PVCs was the only inclusion criterion. Forty-four subjects (6 females and 38 males) aged 18-74 years (mean 547.1 years), were eligible. All had a European Pacemaker Identification Card (EPIC) documenting left ventricular ejection fraction (LVEF). The frequency of recorded episodes of VT and VF was obtained from ICD memory.</AbstractText>Among patients with ischemic heart disease (IHD) and those with IHD and an LVEF of less than 30%, the mean frequency of PVCs was significantly higher in those with subsequent episodes of VT/VF compared to those without subsequent episodes (p &lt; 0.05 for sPVCs and rPVCs in both groups).</AbstractText>Among patients with IHD, mean frequency of PVCs is a useful marker of vulnerability to potentially fatal arrhythmias and may be a useful tool for the risk stratification of patients.</AbstractText>

Traumatic pneumobilia after cardiopulmonary resuscitation.

Pneumobilia is a rare pathological finding, which denotes an abnormal connection between the gastrointestinal and the biliary tract. In the absence of surgically created anastomosis between the bowel and the bile duct, the most common causes for pneumobilia are gallstone obstruction, endoscopic interventions, or emphysematous cholecystitis. We present this case of a middle-aged multiple-injured male who developed traumatic pneumobilia after cardiopulmonary resuscitation. We suppose that chest compression in combination with a sphincter of Oddi (SO) dysfunction forced intraluminal air retrograde through the SO into the biliary tract, since intraabdominal injury as well as former biliary pathology, inflammation, or biliary-enteric fistula were excluded.

[Disturbances of cardiac rhythm and metabolic control in patients with type-2 diabetes].

Twenty four hour ECG monitoring, registration of ventricular late potentials, and measurement of glycated hemoglobin (HbA1c) were included into examination of 142 cardiological patients (101 with and 41 without type 2 diabetes). Groups of patients with and without diabetes had similar age and severity of cardiac pathology. Patients with diabetes had more prognostically and hemodynamically unfavorable arrhythmias -- paroxysmal and permanent atrial fibrillation, high grade ventricular extrasystoles (HGVE) and their combinations. Atrial fibrillation and HGVE were more often observed in diabetic patients with HbA1c &lt;7 and &gt;8.5%, respectively. Date of registration of ventricular late potentials in patients with diabetes mellitus (QRSTt &gt;110 ms, LAS40 &gt;37 ms, and RMS &lt;23 mcV) possess high informative power not only in prognosis of HGVE but also evidences for bad control of glycemia.

In-hospital cardiac arrest.

To review the current management of in-hospital cardiac arrest and to identify variables that influence outcomes, OLDMEDLINE from 1950 to 1966 and MEDLINE from 1966 to March 2005 were searched using the keywords cardiopulmonary resuscitation, cardiac arrest, in hospital, and adult. Secondary sources were derived from review publications and personal communications by one of the authors. There is no secure evidence that the ultimate outcomes after cardiopulmonary resuscitation in settings of in-hospital cardiac arrest have improved in the &gt;40 yrs that followed the landmark report by Kouwenhoven, Jude, and Knickerbocker, which launched the modern era of cardiopulmonary resuscitation. A paucity of objective measurements preclude secure protocols for sequencing of interventions and, even more, when to initiate and discontinue cardiopulmonary resuscitation. The preparedness of both physicians and nursing professionals to implement the published guidelines has itself been questioned. Whereas early access defibrillation with automated external defibrillators may be of benefit in out-of-hospital settings, there has as yet been no secure evidence that automated external defibrillators have had a favorable impact on in-hospital cardiopulmonary resuscitation when used on infrequent occasions by first responders. This contrasts with the much greater success of advanced life support providers and especially when electrical defibrillation is promptly performed by expertly trained personnel after onset of cardiac arrest. Outcomes are therefore improved in critical care settings and especially in coronary care units in which patients are continuously monitored.

Biplane assessment of left ventricular function during atrial fibrillation at beats with equal subsequent cycles.

Prior study has demonstrated that the biplane single-beat method could be used to assess left ventricular function during atrial fibrillation at a beat with equal subsequent cycles. The study was to test whether we could improve the method by measuring a few beats with equal subsequent cycles and cycle-length limits.</AbstractText>In 75 patients with atrial fibrillation, stroke volume and ejection fraction were determined from simultaneous biplane views of left ventricle for 20 beats using a matrix-array transducer and a biplane Simpson's rule. The influence of cycle lengths on the values of systolic parameters at beats with equal subsequent cycles was examined from the plot of normalized parameters (measured values/average values) against cycle lengths. The values of 1 to 3 beats with equal subsequent cycles and cycle-length limits were averaged and compared with the average values over 20 beats by Bland-Altman and mean percentage difference analysis. The variability of repeat measurements was evaluated in 10 patients.</AbstractText>The systolic parameters measured at beats with cycle lengths shorter than 500 ms were usually far below the average values. Agreement and mean percentage difference analysis revealed improved accuracy when 2 or 3 beats with cycle-length limits (&gt;500 ms) were used for assessment. As the variability of averaging 2 or 3 beats is no greater than that of repeat measurements, both methods are equally good.</AbstractText>Accurate assessment of left ventricular systolic function in atrial fibrillation can be obtained by averaging 2 beats with equal subsequent cycles and cycle-length limits (&gt;500 ms).</AbstractText>

The stentless xenograft aortic valve: the wheel turns around.

A brief overview of the historical pathways of both stented and stentless porcine xenografts is presented in order to understand the return to and continuing clinical use of stentless devices. In addition, 7-11 years of durability with various models of stentless porcine valves has now accumulated and is beginning to be of relevance in determining the future place of this xenograft. Stentlessness and anticalcium agents, coupled with the poor results of stented xenografts in certain patient groups, have led to a resurgence of the clinical use of stentless xenograft valves for aortic valve replacement. An overview of the present state and future of stentless valves is given.</AbstractText>At both The Prince Charles Hospital and St Andrew's War Memorial Hospital, Queensland, Australia, 307 patients have received the Model 300 CryoLife-O'Brien stentless composite aortic xenograft from December 1992 to February 2000. Associated procedures were required in 56% of patients (mostly coronary artery bypass, mean 2.4 grafts, in 144 patients (47%) and left ventricular myomectomy in 34 patients (11%)).</AbstractText>The hospital mortality (four early deaths) has been 1.3 +/- 1% (CL 95%) and the follow-up 100% for this analysis. The mean patient age was 73 years (range 57-89 years with 16% being 80 years and over). Morbid events have included six perivalvar leaks: four trivial and identified only on echo Doppler (no clinical murmurs) and two patients requiring reoperation at 10 days and 12 weeks with simple successful repair verified on subsequent echocardiograms. Of the 307 patients over the 7 year period, three valves only have been explanted, two for endocarditis at 1.5 and 3.5 years and one for possible technically induced structural failure at 15 months (probable needle damage). With this exception, there has been as yet no other intrinsic leaflet failure. Four early thromboembolic events (4 days-5 weeks) in patients with atrial fibrillation (no anticoagulants used postoperatively with the first 80 patients) constituted the important early morbid events. Late mortality of this elderly patient cohort has occurred in 27 patients over 7 years of maximum follow-up. One death (endocarditis) has been valve related at 5 years. Serial echocardiography (some 700 echoes in the study of this valve) has demonstrated a mean gradient of 7-9 mmHg with a very low incidence of trivial incompetence (96%) on Doppler examination with implant valve sizes ranging from 21 to 29 mm. One patient had significant regurgitation requiring reoperation. There has been no progression of either incompetence or stenosis of the remaining patients in this follow-up, now into the eighth postoperative year.</AbstractText>The early and intermediate results appear excellent in this elderly patient cohort. Nevertheless, important surveillance is obviously required to determine the durability at 10-12 years, a crucial time when stented porcine xenografts began to show an obvious failure rate from structural deterioration, in the middle and elderly aged patient cohort. An attempt is made to outline the future of this type of stentless xenograft and to justify that its cautious use should probably be extended down to the over 50 year age patient cohort.</AbstractText>

Comparison of intravenous ibutilide vs. propafenone for rapid termination of recent onset atrial fibrillation.

This study was to evaluate the efficacy and safety of ibutilide and propafenone given intravenously in converting recent onset atrial fibrillation (AF). Eighty-two consecutive patients with AF (onset in 2 h to 90 days) were randomly assigned to receive two 10-min infusions, 10 min apart, of either ibutilide (1 mg) or propafenone (70 mg). The treatment was considered successful if sinus rhythm occurred within 90 min after the beginning of infusion. Ibutilide had a significantly higher rate of cardioversion than propafenone (70.73 vs. 48.78%, p = 0.043). The patients with shorter AF duration or smaller left atrium diameter had a higher success rate. Nonsustained monomorphic ventricular tachycardia was the most serious adverse effect of ibutilide in 9.76% of patients, and hypotension and heart pause were the major serious adverse events in 17.07% of patients treated with propafenone. Ibutilide is more effective than intravenous propafenone for the cardioversion of recent onset AF, and the adverse effects are rare and transient.

Cardiac histological substrate in patients with clinical phenotype of Brugada syndrome.

The role of structural heart disease and sodium channel dysfunction in the induction of electrical instability in Brugada syndrome is still debated.</AbstractText>We studied 18 consecutive patients (15 males, 3 females; mean age 42.0+/-12.4 years) with clinical phenotype of Brugada syndrome and normal cardiac structure and function on noninvasive examinations. Clinical presentation was ventricular fibrillation in 7 patients, sustained polymorphic ventricular tachycardia in 7, and syncope in 4. All patients underwent cardiac catheterization, coronary and ventricular angiography, biventricular endomyocardial biopsy, and DNA screening of the SCN5A gene. Biopsy samples were processed for histology, electron microscopy, and molecular screening for viral genomes. Microaneurysms were detected in the right ventricle in 7 patients and also in the left ventricle in 4 of them. Histology showed a prevalent or localized right ventricular myocarditis in 14 patients, with detectable viral genomes in 4; right ventricular cardiomyopathy in 1 patient; and cardiomyopathic changes in 3. Genetic studies identified 4 carriers of SCN5A gene mutations that cause in vitro abnormal function of mutant proteins. In these patients, myocyte cytoplasm degeneration was present at histology, whereas terminal dUTP nick end-labeling assay showed a significant increase of apoptotic myocytes in right and left ventricle versus normal controls (P=0.014 and P=0.013, respectively).</AbstractText>Despite an apparently normal heart at noninvasive evaluation, endomyocardial biopsy detected structural alterations in all 18 patients with Brugada syndrome. Mutations in the SCN5A gene, identified in 4 of the 18 patients, may have induced concealed structural abnormalities of myocardiocytes that accounted for paroxysmal arrhythmic manifestations.</AbstractText>

Pharmacogenetics and cardiac ion channels.

Ion channels control electrical excitability in living cells. In mammalian heart, the opposing actions of Na(+) and Ca(2+) ion influx, and K(+) ion efflux, through cardiac ion channels determine the morphology and duration of action potentials in cardiac myocytes, thus controlling the heartbeat. The last decade has seen a leap in our understanding of the molecular genetic origins of inherited cardiac arrhythmia, largely through identification of mutations in cardiac ion channels and the proteins that regulate them. Further, recent advances have shown that 'acquired arrhythmias', which occur more commonly than inherited arrhythmias, arise due to a variety of environmental factors including side effects of therapeutic drugs and often have a significant genetic component. Here, we review the pharmacogenetics of cardiac ion channels-the interplay between genetic and pharmacological factors that underlie human cardiac arrhythmias.

Flecainide overdose--support using an intra-aortic balloon pump.

Flecainide is an antiarrhythmic agent which is being used increasingly for the management of super-ventricular arrhythmias. Overdose with flecainide is frequently fatal with mortality reported as high as 22% due to arrhythmias, myocardial depression and conduction defects leading to electro-mechanical dissociation and asytole. Supportive measures are often required during the case and previously have included inotropes, extracorporeal membrane oxygenation and cardiopulmonary bypass.</AbstractText>A 47 year old lady presented to the emergency department with a four hour history of severe central chest pain. Her ECG showed atrial fibrillation and broad QRS complexes with a sine wave appearance. She had a past history of paroxysmal atrial fibrillation and significant psychiatric history. Following thrombolysis for a presumed myocardial infarction she developed cardiogenic shock with severely impaired left ventricular function. An intra-aortic balloon pump was inserted and coronary angiography demonstrated normal coronary arteries. With inotropic support she improved over 48 hours, with both her QRS duration and left ventricular function returning to normal. Biochemical testing following her discharge demonstrated significantly elevated levels of flecainide.</AbstractText>The use of an intra-aortic balloon pump is a useful supportive measure during the acute phase of flecainide overdose associated with severe myocardial depression.</AbstractText>

Impact of atrioventricular node ablation and pacing therapy on clinical course in patients with permanent atrial fibrillation and unstable ventricular tachycardia induced by rapid ventricular response: follow-up study.

To evaluate prospectively the impact of atrioventricular (AV) node ablation and consequent pacing therapy on clinical course in patients with permanent atrial fibrillation and unstable ventricular tachycardia induced by rapid ventricular response.</AbstractText>One hundred four patients with permanent atrial fibrillation and uncontrolled ventricular rate resistant to drug therapy underwent radiofrequency catheter ablation of the AV node and permanent pacemaker implantation. At baseline examination, 14 of them had unstable ventricular tachycardia induced by rapid ventricular response of atrial fibrillation (ventricular tachycardia group). The remaining 90 patients did not have this type of ventricular tachycardia (control group). After the ablation, all patients were followed-up without antiarrhythmic agents. The primary end point was sudden cardiac death.</AbstractText>Before the ablation, patients in ventricular tachycardia group had lower left ventricular ejection fraction (P&lt;0.013), and higher ventricular rate at rest and during daily activities (P&lt;0.001). During the follow up of 20+/-8 months (mean+/-standard deviation), the mortality rate of sudden cardiac death at two years was similar among the two groups (7% vs 5%, P=0.703). The observed cardiac and all-cause mortality were significantly higher in ventricular tachycardia group (21% vs 3.6%, P=0.014; 28.5% vs 4.4%, P=0.038; respectively) due to increased heart failure-related mortality (P=0.013).</AbstractText>In patients with permanent atrial fibrillation and ventricular tachycardia induced by rapid ventricular response, AV node ablation and pacing therapy have beneficial effect in the elimination of this arrhythmia. It seems that these patients do not need a cardioverter defibrillator therapy.</AbstractText>

Ventricular pacing vs dual chamber pacing in patients with persistent atrial fibrillation after atrioventricular node ablation: open randomized study.

To compare ventricular rate responsive (VVIR) pacing with dual chamber rate responsive (DDDR) pacing and antiarrhythmic drugs for the treatment of patients with persistent atrial fibrillation after atrioventricular node ablation.</AbstractText>One hundred two patients with persistent atrial fibrillation eligible for the atrioventricular node ablation were randomly assigned to the therapy with either VVIR pacemaker (n=52) or DDDR pacemaker and antiarrhythmic drugs (n=50). After ablation, patients in both pacing groups were assigned to take anticoagulant therapy. The primary end point was stroke or death from cardiovascular causes.</AbstractText>After a mean follow-up of 26.6+/-9.5 months, there was no difference in the stroke or death rates between patients with VVIR pacing (6 or 5.2% per year) and those with DDDR pacing and antiarrhythmic drugs (6 or 5.9% per year, P=0.930). The observed rates of death from all causes, hospitalization for heart failure, and myocardial ischemia were similar in the two patient groups. There was a significantly lower rate of development of permanent atrial fibrillation in patients with DDDR pacing and antiarrhythmic drugs, with a reduction in absolute risk by 56% and relative risk by 64% (32% vs 88%; P&lt;0.001).</AbstractText>With respect to cardiovascular death and morbidity, VVIR pacing is not inferior to DDDR pacing and antiarrhythmic drugs for the treatment of patients with persistent atrial fibrillation after atrioventricular node ablation and may be considered as an appropriate therapy for such patients.</AbstractText>

In-hospital cardiac arrest and resuscitation outcomes: rationale for sudden cardiac death approach.

To assess the frequency of cardiac arrest and outcomes and predictors of survival after cardiopulmonary resuscitation in hospitalized patients.</AbstractText>We prospectively analyzed the data on all patients who experienced cardiac arrest while hospitalized at the Split University Hospital between January and December 2003. Data were collected on patients' demographic characteristics, etiology and presentation of cardiac arrest, time, site, methods, and outcomes of cardiopulmonary resuscitation.</AbstractText>Out of 120 cases of cardiac arrest among 32,861 hospitalized patients, 76.7% were witnessed. Ninety-six (80.0%) patients with cardiac arrest underwent resuscitation, and 22.5% of them were discharged alive. The survival rate was 20.0% at the Department of Internal Medicine, 29.2% in the Coronary Care Unit, and only 7.1% in other departments (P=0.058, chi2 test). Out of 92 patients with witnessed cardiac arrest, 28.3% survived to discharge, whereas only one of 28 patient with unwitnessed cardiac arrest survived to discharge (P=0.004, Fisher's exact test). More patients with cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia survived than patients with asystole and pulseless electrical activity (47.6% vs 10.7%, respectively, P&lt;0.001, Fisher's exact test). None of the patients with unclassified cardiac arrest survived until discharge. Cardiac arrest survivors were significantly younger (60.8+/-12.9 vs 71.1+/-11.7 years, P&lt;0.001, Student t-test). Sex had no influence on survival. There were no significant circadian or hospital shift differences in the frequency rate of cardiac arrest, but the rate of successful resuscitation was lower during the night shift.</AbstractText>The rate of successful resuscitation was higher in the coronary care unit, during the day and in younger witnessed cardiac arrest patients with ventricular fibrillation or pulseless ventricular tachycardia.</AbstractText>

Morbidity and mortality of hospitalized patients with diffuse idiopathic skeletal hyperostosis.

Diffuse idiopathic skeletal hyperostosis (DISH) has been associated with various metabolic disorders considered to be cardiovascular risk factors such as obesity, diabetes mellitus, hyperinsulinemia, and hyperlipidemia. To evaluate morbidity and mortality of hospitalized patients with DISH admitted to the department of medicine. One hundred patients from a cohort of 1020 consecutive patients, aged 45 years and more, admitted to the department of medicine were diagnosed as suffering from DISH. Another group of 100 patients, age- and gender matched, admitted without DISH, served as controls. Clinical and demographic characteristics, diagnoses on admission, previous chronic diseases, chronic medical therapy, laboratory tests, and the rates of in-hospital mortality and readmissions within 1 month of discharge were collected from the hospital database, for the two groups. Uncompensated or paroxysmal atrial fibrillation was more often encountered on admission in patients with DISH (p = 0.038). Patients with DISH were more likely to suffer from elevated body mass index, arterial hypertension, diabetes mellitus, and previous cerebral vascular accidents, although the differences did not reach statistical significance. However, significantly more patients had an electrocardiographic evidence of left ventricular hypertrophy (p = 0.03). The mortality rate was similar between the two groups. The lack of significant associations for cardiovascular risk factors such as diabetes mellitus, hypertension, and high BMI should be interpreted cautiously considering the characteristics of the control group. Identification of comorbid conditions and proper therapeutic interventions may prove useful in reducing the morbidity and mortality associated with this disorder.

Outcome of out-of-hospital cardiorespiratory arrest in children.

To analyze the characteristics and outcome of out-of-hospital cardiorespiratory arrest in children in Spain.</AbstractText>Secondary analysis of data from a prospective, multicenter study analyzing cardiorespiratory arrest in children. Ninety-five children between 7 days and 16 years with cardiorespiratory arrest. Data were recorded according to the Utstein style. The outcome variables were the sustained return of spontaneous circulation (initial survival), and survival at 1 year (final survival). Neurologic and general performance outcome was assessed by the Pediatric Cerebral Performance Category (PCPC) scale and the Pediatric Overall Performance Category (POPC) scale.</AbstractText>Initial survival was 47.3% and 1-year survival was 26.4%. Mortality was higher in children younger than 1 year. Survival of patients with respiratory arrest (82.1%) was significantly higher than survival of cardiac arrest victims (14.4%). Patients who were initially resuscitated by laypersons or paramedics had higher survival (53.6%) than those who were initially resuscitated by doctors and/or nurses (15.2%) (P &lt; 0.01). Mortality was higher in the patients who presented slow rhythms (asystole, severe bradycardia) or pulseless electrical activity than in those presenting ventricular fibrillation (P = 0.001). Multivariate logistic regression revealed that the best indicator of mortality was duration of cardiopulmonary resuscitation longer than 20 minutes. After 1 year, most survivors had normal or mild disability.</AbstractText>Mortality of out-of-hospital cardiorespiratory arrest in children is high. When resuscitation is started soon by layperson or paramedics, survival is increased. Duration of resuscitation efforts is the best indicator of mortality. Most of survivors had good long-term neurologic outcome.</AbstractText>

The protective effect of H2-receptor activation against the duration of myocardial hypoxia/reoxygenation-induced ventricular fibrillation in sensitized guinea-pig hearts.

Patients with high serum immunoglobulin E levels were reported to be protected against sudden death during acute myocardial infarction. The protection mechanism might be attributed to the facilitation of histamine release from sensitized mast cells; however, this remains to be clarified. In this study, we examined the influence of sensitization on ventricular fibrillation (VF) induced by myocardial hypoxia/reoxygenation (H/R). Guinea pigs were actively sensitized by subcutaneous injection of ovalbumin in Bordetella pertussis vaccine. Hearts isolated from non-sensitized and sensitized guinea pigs were subjected to 30-min hypoxia / 30-min reoxygenation using a Langendorff apparatus. The amount of histamine released in the sensitized guinea-pig hearts was elevated, and the duration of VF was found to be reduced. The treatment with a histamine H2-receptor antagonist inhibited the reduction of VF duration. Treatment of the non-sensitized hearts with the histamine H2-receptor agonist resulted in the decrease of VF duration to the same level as that in the sensitized hearts. In conclusion, these results suggest that the risk of sudden death during myocardial H/R may be attenuated in the sensitized hearts and that histamine H2-receptor activation due to the released histamine may be involved in the protective effect.

Thrombus formation on an atrial septal defect closure device: a case report and review of the literature.

We report on a case of a mobile left atrial thrombus formation on an atrial septal defect occluder system (28 mm StarFLEX-Occluder) despite 6 months of postprocedural anticoagulation with phenprocoumon and platelet antiaggregation with aspirin in a 69-year-old woman. The closure was performed because of a significant left to right atrial shunt (Qp/Qs 1.8) with enlargement of the right atrial and ventricular cavities and impairment of right ventricular function in the presence of persistent atrial fibrillation and chronic heart failure (NYHA II-III). The 6-month follow up by transoesophageal echocardiography (TEE) revealed the floating thrombus located at the left atrial side of the occluder.

[Therapeutic strategies in inappropriate ICD therapy].

20-30% of ICD patients suffer from inappropriate ICD therapy due to misclassification of supraventricular tachycardia (SVT) as ventricular tachycardia. Inappropriate ICD therapies are not only painful for patients, but also proarrhythmogenic and can reduce device longevity due to battery depletion. Therapy of inappropriate ICD episodes is a puzzle of optimized ICD programming, antiarrhythmic therapy and radiofrequency (RF) ablation. Single-chamber ICD detection algorithms are effective in reducing inappropriate ICD therapy particularly due to sinus tachycardia or atrial fibrillation. Dual-chamber ICD detection algorithms were developed to improve specificity of SVT discrimination. However, large prospective, controlled trials showing superiority of dualchamber over single-chamber devices are lacking. It appears that patients with slow ventricular tachycardias, being at high risk for inappropriate ICD therapy, might benefit from dual-chamber ICD therapy. Concerning pharmacological therapy of inappropriate ICD episodes, the OPTIC study recently showed superiority of class III antiarrhythmics (sotalol and amiodarone) over beta-blockers. RF ablation of cavotricuspid isthmus is of proven benefit in ICD patients with inappropriate episodes due to typical flutter and should also be considered in atrial tachycardia. If patients with paroxysmal atrial fibrillation despite optimized antiarrhythmic medication will benefit from trigger elimination or substrate modification by RF ablation has still to be proven. In patients with inappropriate ICD episodes and drug-refractory chronic permanent atrial fibrillation, AV node ablation can effectively eliminate inappropriate ICD therapy, however, at the price of potential ventricular asynchrony and progression of heart failure due to right ventricular pacing. Thus, upgrading to biventricular ICD therapy should be considered in these patients.

[Frequent ventricular tachycardias: antiarrhythmic drug treatment or catheter ablation?].

Antiarrhythmic drugs are used in at least 50% of patients who received an implantable cardioverter defibrillator (ICD). The potential indications for antiarrhythmic drug treatments in patients with an ICD are generally the following: reduction of the number of ventricular tachycardias (VTs) or episodes of ventricular fibrillation and therefore reduction of the number of ICD therapies, most importantly, the number of disabling ICD shocks. Accordingly, the quality of life should be improved and the battery life of the ICD extended. Moreover, antiarrhythmic drugs have the potential to increase the tachycardia cycle length to allow termination of VTs by antitachycardia pacing and reduction of the number of syncopes. In addition, supraventricular arrhythmias can be prevented or their rate controlled. Recently published or reported trials have shown the efficacy of amiodarone, sotalol and azimilide to significantly reduce the number of appropriate and inappropriate ICD shocks in patients with structural heart disease. However, the use of antiarrhythmic drugs may also have adverse effects: an increase in the defibrillation threshold, an excessive increase in the VT cycle length leading to detection failure. In this situation and when antiarrhythmic drugs are ineffective or have to be stopped because of serious side effects, catheter ablation of both monomorphic stable and pleomorphic and/or unstable VTs using modern electroanatomic mapping systems should be considered. The choice of antiarrhythmic drug treatment and the need for catheter ablation in ICD patients with frequent VTs should be individually tailored to specific clinical and electrophysiological features including the frequency, the rate, and the clinical presentation of the ventricular arrhythmia. Although VT mapping and ablation is becoming increasingly practical and efficacious, ablation of VT is mostly done as an adjunctive therapy in patients with structural heart disease and ICD experiencing multiple shocks, because the recurrence and especially the occurrence of "new" VTs after primarily successful ablation with time and disease progression have precluded a widespread use of catheter ablation as primary treatment.

[Is DFT testing still mandatory?].

The automatic detection and termination of ventricular fibrillation is still the key function of implantable cardioverter defibrillator (ICD) therapy. The progress in generator and lead technology has overcome limitations in defibrillation efficacy in early transvenous defibrillator devices. Current, active pectoral biphasic devices provide a high defibrillation efficacy. More than 90% of all patients will meet accepted implantation criteria without any intraoperative system modifications. Is this enough to abandon the intraoperative assessment of defibrillation efficacy? Arguments for abandoning intraoperative device testing include: reduction of perioperative complications, time and cost saving, no worse prognosis for defibrillator patients with borderline defibrillation efficacy, DFT testing might be a barrier to an easy access to ICD implantation. Abandoning intraoperative assessment of defibrillation efficacy may result in inadequate defibrillation safety in up to 9% of all patients. The noninferior outcome of patients with nonadequate defibrillation efficacy is not already proven. Intraoperative device testing could be limited to a small number of VF inductions, the safety of these protocols is well established. A significant time and cost reduction is not really existing. The abandoning of defibrillation testing will not lead to an increase in ICD implant capacity. The intraoperative assessment of defibrillation efficacy should be an important part of ICD implantation.

[Cardiac pacing for the prevention of atrial fibrillation. A current review].

Several prospective randomized clinical trials have reported that atrial-based "physiological" pacing is associated with a lower incidence of paroxysmal and permanent atrial fibrillation than single-chamber ventricular pacing in patients with conventional pacemaker indication. Whether atrial pacing itself is antiarrhythmic remains still uncertain. By contrast, right ventricular pacing is considered to beget atrial fibrillation, even in preserved AV synchrony during dual-chamber pacing. A number of clinical trials investigated the impact of sitespecific atrial pacing and advanced atrial pacing algorithms on the secondary prevention of atrial fibrillation. Multisite pacing (dual-site right atrial or biatrial pacing) was demonstrated to add only minimal benefit for the prevention of atrial fibrillation. By contrast, in some studies septal pacing and specific atrial pacing algorithms were reported to reduce the recurrence of atrial fibrillation in selected patients. At present, however, it remains unclear how to identify these patients. In clinical practice, the effectiveness of specific atrial pacing algorithms and/or septal pacing has to be tested out in the individual case. These therapeutic options should be considered in patients with a conventional indication for antibradycardia pacing and, additionally, symptomatic atrial fibrillation.

Risk factors of ventricular tachyarrhythmias after coronary artery bypass grafting.

Ventricular arrhythmias are rare and represent the most serious arrhythmic complication after coronary artery bypass grafting (CABG).</AbstractText>The present retrospective study was conducted for identifying patients at risk of ventricular arrhythmias with ventricular signal averaged ECG, standard deviation of all normal RR intervals (SDNN), angiographic and echocardiographic data. We defined ventricular arrhythmias as sustained ventricular fibrillation and ventricular tachycardia. The study population consisted of 209 consecutive patients with sinus rhythm undergoing CABG. The primary endpoint was the occurrence of VA after CABG. The secondary endpoints were hospital length of stay after CABG and the occurrence of VA after hospital discharge.</AbstractText>During the postoperative follow-up ventricular arrhythmias were observed in 11 patients (5%). Patients with ventricular arrhythmias showed a higher incidence of ventricular late potentials (91 vs. 9% of patients, p&lt;0.0001) than patients without ventricular arrhythmias. In addition patients with ventricular arrhythmias had a lower left ventricular ejection fraction (44.2+/-15.2 vs. 60.1+/-13.1%, p&lt;0.0001) and a SDNN (22.4+/-8.8 vs. 34.4+/-16.1 ms, p&lt;0.02). A stepwise logistic regression analysis of all variables identified the combination of ventricular late potentials, ejection fraction &lt; or = 38% and SDNN &lt; or = 28 ms (odds rate 26.00; 95% CI, 3.44-196.67, p&lt;0.002) as an independent predictor of ventricular arrhythmias.</AbstractText>The results of our study suggest that the probability of ventricular arrhythmias could be predicted after CABG by a combination of low left ventricular ejection fraction and a measurement of ventricular signal averaged ECG and standard deviation of all normal RR intervals. Patients who can be identified as having a high risk of ventricular arrhythmias should be observed carefully after surgery.</AbstractText>

Aneurysm involving bifurcation of left main coronary artery presenting with transient ischemic attack, paroxysmal atrial fibrillation and ventricular tachycardia.

Coronary artery aneurysm, especially left main coronary artery (LMCA) aneurysm is a rare phenomenon. The disease may be congenital or acquired. The most common cause of coronary artery aneurysm is atherosclerosis. We presented a man with a large LMCA aneurysm presenting with unstable angina, transient ischemic attack, ventricular tachycardia and paroxysmal atrial fibrillation.

[Inhibition of the muscarinic potassium current by KB130015, a new antiarrhythmic agent to treat atrial fibrillation].

Vagus-induced atrial fibrillation is of particular clinical interest. The muscarinic potassium current I(K(ACh)) mediates the induction of vagus-induced atrial fibrillation. Selective inhibition of I(K(ACh)) seems to be an option to treat atrial fibrillation. The application of amiodarone, presently one of the most important antiarrhythmic agents in the parmacological treatment of atrial fibrillation, is limited by its adverse effects. KB130015, a new amiodarone derivative, and ibutilide are new class III antiarrhythmic agents.</AbstractText>In guinea-pig atrial myocytes the muscarinic potassium current (I(K(ACh))) was activated by acetylcholine and adenosine. The effect of KB130015 on I(K(ACh)) was measured using the whole-cell voltage-clamp method.</AbstractText>KB130015 and ibutilide in a concentration of 50 microM effectively inhibited the muscarinic potassium current. The effect was concentrationdependent and reversible. The half-maximum effective concentration was 0.8 microM (KB130015) and 2.8 microM (ibutilide). The inhibition of I(K(ACh)) was independent of the mode of its activation. The adenosine-induced ion current was as well inhibited by both drugs as the acetylcholine-induced ion current. Via GTP-gamma-S irreversibly activated I(K(ACh)) was also inhibited by KB130015 and ibutilide, whereas intracellular application showed no effect on I(K(ACh)).</AbstractText>KB130015 and ibutilide are potent inhibitors of IK(ACh). Their effect is most likely mediated by direct interaction with the extracellular part of the ion channel. Acute effects of KB130015 on ventricular myocardium are not known so far. Ibutilide on the other hand is known to inhibit I(kr). KB130015 is a promising antiarrhythmic agent for the pharmacotherapy of vagus-induced atrial fibrillation.</AbstractText>

Vascular dementia prevention: a risk factor analysis.

Brain injury from ischemic or hemorrhagic cerebrovascular disease (CVD) produces decline in cognitive functions and vascular dementia (VaD). Likewise, CVD may cause VaD from hypoperfusion of susceptible brain areas. CVD may also worsen degenerative dementias such as Alzheimer's disease. Significant advances have been made in the identification and control of risk factors for stroke and cardiovascular disease. The main risk factors for VaD include age, hypertension and absence of antihypertensive medication, diabetes, cigarette smoking, history of cardiovascular disease (coronary heart disease, congestive heart failure, peripheral vascular disease), atrial fibrillation, left ventricular hypertrophy, hyperhomocysteinemia, orthostatic hypotension, cardiac arrhythmias, hyperfibrinogenemia, and sleep apnea. Recently identified risk factors include chronic infection and elevation of C-reactive protein, particularly in patients with diabetes. Evidence from controlled clinical trials strongly suggests that control of vascular risk factors, in particular hypertension, could prevent the development of dementia.

Recovery of systolic and diastolic function after ablation of incessant supraventricular tachycardia.

We report a case of a 26-year-old woman who presented to our hospital with arrhythmia and heart failure. She had an incessant supraventricular tachycardia, which was not reversible with electrical cardioversion. Echocardiogram showed a severe LV systolic and diastolic dysfunction. After radiofrequency catheter ablation, LV function returned to normal. This article is intended to show a case with tachycardiomyopathy, which is considered the most frequently unrecognized curable cause of heart failure, and to demonstrate that early treatment allows the recovery to a normal LV systolic and diastolic function, preventing irreversible structural cardiac damage. It is very likely that some patients with idiopathic dilated cardiomyopathy and chronic atrial fibrillation or other chronic arrhythmia actually have a curable tachycardiomyopathy.

Influence of spinal anesthesia on corrected QT interval.

Prolongation of the QT interval may result in grave cardiac arrhythmias, polymorphic ventricular tachycardia ("torsades de pointes"), and ventricular fibrillation. We assessed the influence of spinal anesthesia on the QTc interval and the potential arrhythmogenicity of this method of anesthesia.</AbstractText>Assessment was performed in 20 male unpremedicated patients, I or II American Society of Anesthesiologists physical status, who underwent spinal anesthesia for elective surgical procedures. Values of the QTc interval, heart rate, and arterial pressure were measured before spinal anesthesia as well as after 1, 3, 5, and 15 minutes of adequate blockade.</AbstractText>Statistically significant lengthening of the QTc interval (compared with initial values) was observed in the first minute after blockade and in subsequent measurements. No differences were observed between mean values of the QTc interval after the onset of blockade. No significant changes in heart rate were noted. From the third minute on, significant decreases of the systolic, diastolic, and mean arterial blood pressure were observed as compared with baseline. These decreases in systolic, diastolic, and mean arterial blood pressure persisted for the entire study duration. No one patient developed clinically important cardiac arrhythmias.</AbstractText>Spinal anesthesia provokes significant QTc interval prolongation in patients without cardiovascular disorders.</AbstractText>

Incidence and significance of abnormal hepatic venous Doppler flow velocities before cardiac surgery.

The purpose of this study was to determine the incidence and significance of abnormal hepatic Doppler venous flow velocities as signs of an abnormal right ventricular filling pattern before cardiac surgery.</AbstractText>Retrospective and prospective validation study.</AbstractText>Tertiary care hospital.</AbstractText>Cardiac surgical patients (121 patients).</AbstractText>Not applicable.</AbstractText>Demographic, hemodynamic, and echocardiographic variables; vasoactive support; and difficult separation from bypass were compared between patients with or without abnormal hepatic venous Doppler flow. Logistic regression analysis was performed to identify predictors of difficult separation from bypass. Abnormal hepatic venous flow was observed in 23 (29%) and 17 patients (41%) in the retrospective and prospective study. Abnormal hepatic venous flow before surgery was associated with more vasoactive support in both the retrospective (p = 0.0362) and prospective study (p = 0.0163). In the prospective study, abnormal hepatic venous flow was associated with a higher Parsonnet score (p = 0.0005), more atrial fibrillation (p &lt; 0.0001), pacemaker requirement (p = 0.0124), mitral valve replacement (p = 0.0325), reoperation (p = 0.0050), lower mean arterial pressure to pulmonary artery pressure ratio (p = 0.0127), higher wall motion score index (p = 0.0491), and higher incidence of abnormal right ventricular systolic function (p = 0.0139). Abnormal hepatic venous flow was not found to be an independent predictor of difficult separation from bypass.</AbstractText>Abnormal hepatic venous flow velocities before cardiac surgery are frequent and are associated with increased need for vasoactive support after cardiopulmonary bypass. However, it is not an independent predictor of difficult separation from bypass and worse outcome.</AbstractText>

Effectiveness and safety of internal rectilinear biphasic versus monophasic defibrillation in patients undergoing cardiac surgery.

Recently it has been shown that biphasic external shocks are more effective in the treatment of ventricular fibrillation (VF) compared with monophasic external shocks in terms of number of defibrillation attempts and maximal energy used for termination of VF. Biphasic defibrillators apply different biphasic impulse forms, depending on technology. To the authors' knowledge, there are no existing data concerning the effects of rectilinear biphasic internal shocks in patients undergoing cardiac surgery. The purpose of this study was to compare monophasic with rectilinear biphasic internal shock waveforms for termination of VF in patients undergoing cardiac surgery.</AbstractText>One hundred thirty-four patients scheduled for elective cardiac surgery were prospectively randomized either to monophasic (group A) or biphasic (group B) internal defibrillation. Defibrillation was started with 7 J and increased stepwise to 30 J in each group until successful termination of VF after aortic declamping. The number of defibrillations, as well as the cumulative and maximal energy for termination of VF, were determined. Preoperatively, intraoperatively, and postoperatively troponin T, total creatine phosphokinase (CPK), and CPK- MB isoenzymes were measured.</AbstractText>In 64 patients (47%) VF occurred. The groups consisted of 32 patients each. The number of defibrillations (1.3 +/- 0.6 v 1.9+/- 1.2; p = 0.013), maximal energy per patient (7.9 +/- 2.5 v 11.6 +/- 7.32; p = 0.006), and cumulative energy (10.1 +/-6.1 v 21.3 +/- 24.1; p = 0.016) for successful termination of VF were significantly reduced in group B. Troponin T, CPK, and CPK-MB did not differ between groups.</AbstractText>Results of this study indicate that rectilinear biphasic internal defibrillation is more effective in the treatment of VF during cardiac surgery than is monophasic defibrillation. However, no significant difference in myocardial damage could be detected between groups.</AbstractText>

Perioperative cardiac issues: postoperative arrhythmias.

This article reviews current concepts about the diagnosis and acute management of postoperative arrhythmias. A systematic approach to diagnosis of arrhythmias and evaluation of predisposing factors is presented, followed by consideration of common bradyarrhythmias and tachyarrhythmias in the postoperative setting. Postoperative arrhythmias are common and represent a major source of morbidity after surgical procedures, both cardiac and noncardiac. Postoperative dysrhythmias are most likely to occur in patients with structural heart disease. The initiating factor for an arrhythmia following surgery is usually a transient insult such as hypoxemia, cardiac ischemia, catecholamine excess, or electrolyte abnormality. Management includes correction of these imbalances and, if clinically indicated, medical therapy directed at the arrhythmia itself.

Continuous renal replacement therapy may aid recovery after cardiac arrest.

We report on the case of a patient who suffered a cardiac arrest in ventricular fibrillation (VF), leading to a decerebrate state, who made a rapid complete neuronal recovery following the institution of continuous renal replacement therapy (CRRT). Continuous veno-venous haemodiafiltration (CVVHDF) was used; the patient remained haemodynamically stable. Flexor responses were seen after 1 1/2 h and the patient regained consciousness within 3 h. There were no complications associated with the procedure except some minor gastric bleeding, which did not need any specific therapy.

Augmentation of tissue perfusion by a novel compression device increases neurologically intact survival in a porcine model of prolonged cardiac arrest.

This study was performed to determine the potential efficacy of an automated device with a load-distributing band (AutoPulse, Revivant Corporation), in improving neurologically intact survival after cardiac arrest.</AbstractText>Randomized, controlled trial.</AbstractText>University animal laboratory.</AbstractText>Forty-four swine (18-23 kg).</AbstractText>Eight minutes after induction of untreated ventricular fibrillation, pigs were randomized to AutoPulse-CPR (A-CPR, n = 22), conventional cardiopulmonary resuscitation (CPR) with 20% anterior-posterior chest displacement (C-CPR20, n = 10) or 30% chest displacement (C-CPR30, n = 12), followed by resuscitation protocol with ventilation, defibrillation and intravenous epinephrine (adrenaline).</AbstractText>Aortic and right atrium blood pressure was measured with micromanometers. Regional blood flows were measured with microspheres. Coronary perfusion pressure during A-CPR was significantly higher as compared to C-CPR without epinephrine (A-CPR versus C-CPR20 versus C-CPR30; 16 +/- 1 mmHg versus 7 +/- 2 mmHg versus 11 +/- 2 mmHg, p &lt; 0.05). A-CPR improved both myocardial flow without epinephrine (A-CPR versus C-CPR20 versus C-CPR30; 23% versus 0% versus 4%; percent of baseline, p &lt; 0.05) and cerebral blood flow (40% versus 4% versus 19%, percent of baseline, p &lt; 0.05). Sixteen of 22 animals receiving A-CPR regained spontaneous circulation and survived; 14/22 had normal cerebral performance (CPC 1). Four of 12 animals receiving C-CPR30 regained spontaneous circulation and survived, but only one animal had normal neurological function (14/22 versus 1/12, p &lt; 0.0001). No animal receiving C-CPR20 achieved spontaneous circulation. At necropsy, 67% of C-CPR30 had rib fracture and 33% showed lung injury, while A-CPR and C-CPR20 resulted in no detectable injuries.</AbstractText>Improved hemodynamics with AutoPulse performed CPR results in improved neurologically intact survival without subsequent thoracic or pulmonary injuries in this porcine model of prolonged cardiac arrest.</AbstractText>

Characteristics and short-term survival of individuals with out-of-hospital cardiac arrests in the East Bohemian region.

We describe survival after admission to hospital from out-of-hospital cardiac arrest (OHCA) in the East Bohemian region, according to the Utstein Style guidelines and have identified the main diagnosis including in those who died and had an autopsy.</AbstractText>Over a period of 29 months we used a questionnaire supplied to 24 rescue stations, to identify 718 individuals (511 men and 207 women, aged 16-97 years) with confirmed cardiac arrest who were considered for resuscitation.</AbstractText>Out of 560 patients in whom cardiopulmonary resuscitation for OHCA of confirmed cardiac aetiology was attempted, 350 patients (62.5%) died in the field and 61 (10.9%) died during transport. Hospital admission was achieved in 149 cases (26.6%) and, of these, 96 patients died. Fifty-three patients (9.5%) were discharged home alive, 36 (6.4%) with an intact CNS. The first monitored rhythm showed asystole in 264 cases (47.1%) followed by ventricular fibrillation in 227 cases (40.5%). The main diagnosis of coronary heart disease (CHD) was established clinically in 467 cases (83.4%). In 175 autopsy reports this diagnosis was noted in 152 cases (86.9%).</AbstractText>Of patients resuscitated for OHCA of cardiac aetiology, 9.5% survived to leave the acute hospital. CHD was the principle diagnosis in the entire group and this correlated with the same finding in the group of patients who received an autopsy.</AbstractText>

The effect of global hypoxia on myocardial function after successful cardiopulmonary resuscitation in a laboratory model.

Most laboratory studies of cardiac arrest use models of ventricular fibrillation, but in the emergency room, operating room or intensive care unit, cardiac arrest frequently results from asphyxia. We sought to investigate the effect of different durations of asystole secondary to asphyxia on myocardial function after resuscitation. In a laboratory based experimental series, anaesthetized rats received either 4 or 8 min of asphyxial cardiac arrest, and following standardized resuscitation, serial transthoracic echocardiography was performed. Severe depression of left ventricular fractional shortening occurred in both groups with partial recovery only in the 4-min arrest group, while left ventricular end-diastolic diameter was increased in the 4-min group. The pH, HCO3(-) and SBE were reduced in both groups after resuscitation, but the degree of acidosis was greater in the 8-min group. In this model, transthoracic echocardiography demonstrated both systolic and diastolic impairment following asphyxial cardiac arrest, and a clear dose-effect relationship between duration of asphyxia and degree of impairment. A shorter duration of asphyxia was associated with a lesser increase in left ventricular end-diastolic dimension, compared with more protracted asphyxia; the shorter arrest was associated with better recovery of contractile function and acidosis. Increased duration of asphyxia causes increased systolic and diastolic dysfunction. These findings may have significant implications for resuscitative therapeutics. ECHO assessment may permit specific targeting of therapy directed towards systolic or diastolic function during CPR.

New paradigms in cardiovascular medicine: emerging technologies and practices: perioperative genomics.

Considerable progress has been made in understanding the pathophysiology of perioperative stress responses and their impact on the cardiovascular system; however, researchers are just beginning to unravel genetic and molecular determinants that predispose to increased risk for postoperative cardiovascular adverse events. A new field, coined perioperative genomics, aims to apply functional genomic approaches to uncover the biological reasons why similar patients can have dramatically different clinical outcomes after surgery. For the perioperative physician, such findings may soon translate into prospective risk assessment incorporating genomic profiling of markers important in inflammatory, thrombotic, vascular, and neurologic responses to perioperative stress, with implications ranging from individualized additional pre-operative testing and physiological optimization, to perioperative decision-making, choice of monitoring strategies, and critical care resource utilization. We review current knowledge regarding genomic technologies in perioperative cardiovascular disease characterization and outcome prediction, as well as discuss future trends/challenges for translating integrated "omic" information into daily clinical management of the surgical patient.

[Amiodarone: treatment or cause of atrial fibrillation?].

Amiodarone has long been the anti-arrhythmic drug of choice for the treatment of atrial fibrillation. We use a clinical case report to illustrate the difficulty of treating this arrhythmia, which is frequent in older adults, by explaining the physiopathology of one of its side effects: hyperthyroidism. TSH should be measured in patients with recurrent atrial fibrillation under treatment in order to exclude an amiodarone-induced thyroid dysfunction. In the geriatric population, the control of ventricular rate is often preferred over a conversion in sinus rhythm because the anti-arrhythmic drugs used for conversion have serious side effects.

Effects of endurance exercise training on heart rate variability and susceptibility to sudden cardiac death: protection is not due to enhanced cardiac vagal regulation.

Low heart rate variability (HRV) is associated with an increased susceptibility to ventricular fibrillation (VF). Exercise training can increase HRV (an index of cardiac vagal regulation) and could, thereby, decrease the risk for VF. To test this hypothesis, a 2-min coronary occlusion was made during the last min of a 18-min submaximal exercise test in dogs with healed myocardial infarctions; 20 had VF (susceptible), and 13 did not (resistant). The dogs then received either a 10-wk exercise program (susceptible, n=9; resistant, n=8) or an equivalent sedentary period (susceptible, n=11; resistant, n=5). HRV was evaluated at rest, during exercise, and during a 2-min occlusion at rest and before and after the 10-wk period. Pretraining, the occlusion provoked significantly (P&lt;0.01) greater increases in HR (susceptible, 54.9+/-8.3 vs. resistant, 25.0+/-6.1 beats/min) and greater reductions in HRV (susceptible, -6.3+/-0.3 vs. resistant, -2.8+/-0.8 ln ms2) in the susceptible dogs compared with the resistant animals. Similar response differences between susceptible and resistant dogs were noted during submaximal exercise. Training significantly reduced the HR and HRV responses to the occlusion (HR, 17.9+/-11.5 beats/min; HRV, -1.2+/-0.8, ln ms2) in the susceptible dogs; similar response reductions were noted during exercise. In contrast, these variables were not altered in the sedentary susceptible dogs. Posttraining, VF could no longer be induced in the susceptible dogs, whereas four sedentary susceptible dogs died during the 10-wk control period, and the remaining seven animals still had VF when tested. Atropine decreased HRV but only induced VF in one of eight trained susceptible dogs. Thus exercise training increased cardiac vagal activity, which was not solely responsible for the training-induced VF protection.

Left atrium: no longer neglected.

Left atrial evaluation is strongly linked to the history of cardiac imaging. In the past, the importance of this chamber has been largely downplayed because cineangiography could not visualize it directly. Nowadays echocardiography can easily assess left and right atrial size and function. Left atrial enlargement is frequent in many cardiac diseases. A main determinant of left atrial volume is ventricular diastolic function. It has recently been suggested that left atrial volume might be the morphophysiologic expression of chronic diastolic function. In fact the left atrium is exposed directly to left ventricular diastolic pressure through the open mitral valve and because of its thin wall structure it tends to dilate with increasing pressure. Other important determinants of atrial volume are the degree of ventricular remodeling, mitral regurgitation and the presence of atrial fibrillation. The degree of left atrial enlargement is associated with adverse prognosis in different clinical settings. Patients with dilated cardiomyopathy and with a left atrial volume &gt; 68 ml/m2 have a 3.8-fold risk compared with those with smaller left atrial volume. The predictive value of left atrial volume is independent of left ventricular systolic and diastolic function, mitral regurgitation and atrial fibrillation. This is noteworthy because these factors are both determinant of left atrial volume and have a strong impact on outcome. It might be concluded that left atrial volume represents a powerful predictive marker because it is a window allowing comprehensive evaluation of several factors associated with bad prognosis, which are often difficult to document separately.

Cardiovascular morbidity and mortality in thyroid dysfunction.

This review summarizes present knowledge from clinical and epidemiological studies with respect to cardiovascular complications in thyroid disorders, focusing on cardiovascular morbidity and mortality. Consistently, good evidence exists for an increased cardiovascular morbidity in overt hyperthyroidism, and an association with predictors of cardiovascular mortality like ventricular hypertrophy, ventricular dysfunction, and atrial fibrillation. As for subclinical hyperthyroidism evidence is conclusive only with respect to an up to 5.2-fold elevated risk for atrial fibrillation. The cardiovascular risk profile of overt hypothyroidism is characterized mainly by risk factors of atherosclerosis such as hypercholesterolemia and hypertension, but also by possible development of heart failure. In contrast, data on such parameters are inconsistent for subclinical hypothyroidism. Although many of these cardiovascular alterations may hypothetically worsen prognosis, results from cohort and retrospective studies do not consistently point towards increased mortality. Only for overt hyperthyroidism an up to 1.7 fold elevated risk for cardiovascular diseases and up to 1.7 fold increased cardiovascular mortality rates have been demonstrated. However, the evidence for similarly increased cardiovascular morbidity and mortality rates in subclinical hyperthyroidism and hypothyroidism is inconclusive, and the evidence is non-existent for overt hypothyroidism. Further randomized clinical studies and population-based cohort-studies are required and should consider major cardiovascular risk factors and adverse cardiovascular events and mortality.

Automating phase singularity localization in mathematical models of cardiac tissue dynamics.

Electrical wave-fronts are responsible for contraction in heart tissue. Rotary wave-fronts break up into daughter waves and it is this break up that is believed to underlie ventricular fibrillation. Mathematical methods abound for simulation of fibrillation, and localizing the core of rotary wave-fronts (the phase singularities) is key to characterizing the state of fibrillation and effectiveness of defibrillation in these models. We present a formal method for automating this process in these various models. Automation will allow for side-by-side comparisons of suggested mechanisms of fibrillation, comparison of various models of these mechanisms and faster evaluation of defibrillation strategies making use of these models.

[A case of cardioembolic brain infarction in arrhythmogenic right ventricular dysplasia].

We report a 45-year-old woman with arrhythmogenic right ventricular dysplasia (ARVD). Because of congestive heart failure and atrial fibrillation, she underwent tricuspid valvular replacement and warfarin was prescribed. She suddenly had dysarthria, left hemiparesis and left hemispatial neglect. After brain CT examination, and cerebral angiography, she was diagnosed as cardiogenic brain embolism and infusion of low molecular heparin was started. On day 25, she suddenly had ventricular tachycardia and died in spite of treatment for arrhythmia. This is the first report of the case of cardiogenic brain embolism following ARVD. In this type of case, we must take care of arrhythmia besides the management of atrial fibrillation and brain infarction.

[Tako-tsubo-like syndrome without emotional stress: a case report].

The tako-tsubo-like syndrome (also named left ventricular apical ballooning) is an unusual cardiomyopathy with a high incidence in the Japanese female population, following an emotional stress. The clinical features (typical chest pain), electrocardiographic (negative T wave and persistent ST-segment elevation in anterior leads), echocardiographic (transient left ventricular apical dysfunction with hyperkinesis of basal segments) are suggestive of an acute anterior myocardial infarction; nevertheless all reports in the literature show coronary arteries without angiographic lesions. We report the case of a 77-year-old female (without cardiovascular risk factors) with two prior episodes of paroxysmal atrial fibrillation, who arrived to the emergency department with chest pain, electrocardiographic and echocardiographic features, suggestive of an acute anterior myocardial infarction, not preceded by any emotional stress. Coronary angiography showed coronary arteries without atherosclerotic lesions; left ventriculography showed an anteroapical dysfunction. The follow-up performed with transthoracic echocardiography (2 months later) showed complete regression of regional wall motion abnormalities. The pathophysiological determinant seems to be related to the release of catecholamines (such as epinephrine and norepinephrine) able to create a transient board of ischemic cardiomyopathy through a direct cellular damage.

Radiofrequency catheter septal ablation for hypertrophic obstructive cardiomyopathy in children.

The definitive therapeutic options for symptomatic obstructive cardiomyopathy in childhood are restricted. At present, extensive surgical myectomy is the only procedure that is of proven benefit.</AbstractText>Three patients, aged 5, 11 and 17 years, respectively, with progressive hypertrophic obstructive cardiomyopathy and increasing symptoms were considered for radiofrequency catheter septal ablation. The peak Doppler gradient recorded on several occasions ranged between 50 to 90mmHg. Via a femoral arterial approach, the His bundle was initially plotted and marked using the LocaLisa navigation system. Subsequently, using a cooled tip catheter a series of lesions were placed in the hypertrophied septum, taking care to stay away from the His bundle. A total of 17, 50 and 45 lesions were applied in the three patients. In one case, the procedure was complicated by two episodes of ventricular fibrillation requiring DC cardioversion but without any neurological sequelae.</AbstractText>The preablation peak-to-peak gradient between left ventricle and aorta was 50 mmHg, 60 mmHg and 60 mmHg, respectively, and remained unchanged immediately after the procedure. All patients were discharged from hospital 48 hours later. Serial measurement of serum troponin T and CK-MB isoenzyme confirmed significant myocardial necrosis. Follow-up echocardiography both at seven days and at six weeks postablation confirmed a beneficial haemodynamic result, with reduction of left ventricular outflow obstruction and relief of symptoms.</AbstractText>In young children, in whom alcohol-induced septal ablation is not an option, radiofrequency catheter ablation offers an alternative to surgery, with the benefits of repeatability and a lower risk of procedure-related permanent AV block.</AbstractText>

Coronary risk factors and inflammation in patients with coronary artery disease and internal cardioverter defibrillator implants.

The internal cardioverter defibrillator (ICD) is increasingly used to treat ventricular tachyarrhythmias in patients with coronary artery disease (CAD). The burden of coronary risk factors and inflammation is however not well studied in these high risk patients.</AbstractText>The aim of the present study was to describe the prevalence of coronary risk factors (including lipid values) and inflammation (including high sensitive-C-reactive protein, hs-CRP) in patients with CAD and ICD implants.</AbstractText>Baseline clinical characteristics and laboratory results of all eligible patients for the Cholesterol Lowering and Arrhythmias Recurrences after Internal Defibrillator Implantation trial (CLARIDI trial) were used. All patients had documented CAD, an ICD implant and were not yet treated with statins. Coronary risk factors, lipid values, glycated haemoglobin (HbA(1c)) and hs-CRP levels were determined.</AbstractText>In the 110 included patients (mean age 68+/-9 years, LVEF 40+/-17%, NYHA class II-III in 47%), a high prevalence of coronary risk factors was documented: current smoking in 18%, body mass index &gt; or =30 kg/m(2) in 16%, blood pressure &gt; or =140/90 mm Hg in 40%, history of diabetes in 12%, and HbA(1c) &gt; or =6% in 16% of patients not known with diabetes. A total cholesterol &gt;175 mg/dl was found in 76% of patients and an LDL cholesterol &gt;100 mg/dl in 83%. Finally, median hs-CRP was 4.8 mg/l (interquartile range 2.5-13.9 mg/l). Hs-CRP values &gt; or =2 mg/l were noted in 83% of all patients and in 68% of patients who had an ICD implant more than 6 months before inclusion.</AbstractText>In CAD patients with ICD implants, the burden of coronary risk factors is high, often unrecognized and/or under-treated. Persistent inflammation is found in the majority of these patients.</AbstractText>

Severe dilated cardiomyopathy and quadriceps myopathy due to lamin A/C gene mutation: a phenotypic study.

This study reports a family affected by a new phenotype associated with dilated cardiomyopathy and quadriceps myopathy.</AbstractText>29 family members underwent a physical and neurological examination, including an electromyogram and biopsy of muscle abnormalities. A cardiac examination was performed in all subjects.</AbstractText>The family pedigree (n=72) demonstrated that transmission was autosomal dominant. Eleven subjects had cardiac involvement, only four had quadriceps muscle involvement. Cardiac impairment preceded neurological involvement. The mean age for neurological involvement was 44+/-0.8 years (range 43-45) and cardiac involvement was 37+/-7.9 years (range: 24-45). Cardiac involvement consisted of: hypokinetic dilated cardiomyopathy (64%); atrial fibrillation (100%); ventricular arrhythmias (64%); impaired conduction with bundle branch or complete atrio ventricular block (73%). Four patients required pacemakers and anti arrhythmic therapies. Four patients died: two of refractory heart failure and two of sudden death; two patients were resuscitated following cardiac arrest. Three patients required a prophylactic implantable cardiac defibrillator (ICD). Muscle morphological abnormalities were characterized by a variable number of fibers with rimmed vacuoles. The quadriceps deteriorated progressively without impairment of other muscles. Genotypic study showed a lamin A/C gene mutation.</AbstractText>This family was affected by a new phenotype composed of an autosomal dominant severe dilated cardiomyopathy with conduction defects or arrhythmias and quadriceps myopathy. Cardiac abnormalities preceded neuromuscular disorders and defined the prognosis of this disease.</AbstractText>

Beyond heart rhythms: new directions for implantable devices.

Implantable cardiac devices have become firmly entrenched as important therapeutic tools for a variety of conditions. Pacemakers are the only available treatment for symptomatic bradycardia not due to reversible causes. Large randomized studies have demonstrated a small but statistically significant reduction in atrial fibrillation associated with pacing modes that maintain atrioventricular synchrony. In contrast, pacing mode appears to have a less dramatic effect in patients with atrioventricular block. Cardiac resynchronization with specialized left ventricular leads has been shown to reduce symptoms and improve survival in patients with symptomatic heart failure, systolic dysfunction, and widened QRS complexes. The implantable cardioverter defibrillator has become the standard therapy for protecting patients against sudden cardiac death. Two recent trials, Multicenter Automatic Defibrillator Trial II (MADIT II) and the Sudden Cardiac Death Heart Failure Trial (SCD-HEFT), demonstrated that the ICD is associated with a significant survival benefit for patients with reduced ejection fraction (&lt; 0.30-0.35) particularly if heart failure symptoms are present. Finally the implantable loop recorder has become an important diagnostic tool for the patient with unexplained syncope. This brief overview summarizes the indications and follow-up of the wide array of implantable cardiac devices available to the clinical cardiologist.

Subtraction of 16.67 Hz railroad net interference from the electrocardiogram: application for automatic external defibrillators.

The widespread application of automatic external defibrillators (AEDs) for treating out-of-hospital cardiac arrest incidents and their particular use at railway stations defines the task for 16.67 Hz power line interference elimination from the electrocardiogram (ECG). Although this problem exists only in five European countries, it has to be solved in all AEDs, which must comply with the European standard for medical equipment requirements for interchangeability and compatibility between rail systems. The elimination of the railroad interference requires a specific approach, since its frequency band overlaps with a significant part of the frequencies in the QRS spectra. We present a method based only on one channel ECG signal processing, which effectively subtracts the interference components. The computation procedure is based on simple signal processing tools, which include: (i) bi-directional band-pass filtering (13-23 Hz) of the analyzed ECG segment; (ii) estimation of adequate linearity thresholds; (iii) frequency measurement and calculation of dynamic interference buffer in linear segments and (iv) phase synchronization and subtraction technique in nonlinear segments. The developed method has proved advantageous in providing sufficient quality of the output interference free ECG signal for seven defined arrhythmia types (normal sinus rhythm, normal rhythm, supraventricular tachicardia, slow/rapid ventricular tachycardia, and coarse/fine ventricular fibrillation), and simulated interferences with constant or variable frequencies and amplitudes, which cover the entire amplitude range of the input channel. The procedure is suitable to be embedded in AEDs as a preprocessing branch, which proves reliable for analysis of ECG signals, thus guaranteeing the specified accuracy of the AED automatic rhythm analysis algorithms.

Role of angiotensin system and effects of its inhibition in atrial fibrillation: clinical and experimental evidence.

Atrial fibrillation (AF) is a common arrhythmia that is difficult to treat. Anti-arrhythmic drug therapy, to maintain sinus-rhythm, is limited by inadequate efficacy and potentially serious adverse effects. There is increasing interest in novel therapeutic approaches that target AF-substrate development. Recent trials suggest that angiotensin converting-enzyme (ACE)-inhibitors and angiotensin-receptor blockers (ARBs) may be useful, particularly in patients with left ventricular hypertrophy or failure. The clinical potential and mechanisms of this approach are under active investigation. Angiotensin-II is involved in remodelling and may have direct electrophysiological actions. Experimental studies show protection from atrial structural and possibly electrical remodelling with ACE-inhibitors and ARBs, as well as potential effects on cardiac ion-channels. This article reviews information pertaining to the clinical use and mechanism of action of ACE-inhibitors and ARBs in AF. A lack of prospective randomized double-blind trials data limits their application in AF patients without another indication for their use, but studies under way may alter this in the near future. This exciting field of investigation may lead to significant improvements in therapeutic options for AF patients.

A systematic review and meta-analysis of the impact of omega-3 fatty acids on selected arrhythmia outcomes in animal models.

Epidemiological studies and clinical trials report the beneficial effects of fish or fish oil consumption on cardiovascular disease outcomes including sudden death. We performed a systematic review of the literature on controlled animal studies that assessed the effects of omega-3 fatty acids on selected arrhythmia outcomes. On the basis of predetermined criteria, 27 relevant animal studies were identified; 23 of these were feeding studies, and 4 were infusion studies. Across species, fish oil, eicosapentaenoic acid, and/or docosahexaenoic acid appear to have beneficial effects on ventricular tachycardia (VT) and fibrillation (VF) in ischemia- but not reperfusion-induced arrhythmia models; no effect on the incidence of death and infarct size; and inconsistent results with regard to arrhythmia score, VF threshold, ventricular premature beats or length of time in normal sinus rhythm, compared to omega-6, monounsaturated, or saturated fatty acids, and no treatment controls. In a meta-analysis of 13 studies using rat models, fish oil but not alpha-linolenic acid supplementation showed a significant protective effect for ischemia- and reperfusion-induced arrhythmias by reducing the incidence of VT and VF. It is not known whether omega-3 fatty-acid supplementation has antiarrhythmic effects in other disease settings not related to ischemia.

Hospitalizations for new heart failure among subjects with diabetes mellitus in the RENAAL and LIFE studies.

We sought to study the risk factors for heart failure (HF) and the relation between antihypertensive treatment with losartan and the first hospitalization for HF in patients with diabetes mellitus in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) and Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) studies. We evaluated 1,195 patients with hypertension, left ventricular hypertrophy, and diabetes from the LIFE study and 1,513 patients with type 2 diabetes and nephropathy from the RENAAL study. The comparative treatments were atenolol in the LIFE study and placebo in the RENAAL study. Patients with a history of HF were excluded from this analysis. Losartan significantly reduced the incidence of first hospitalizations for HF versus placebo in the RENAAL study (hazard ratio 0.74, p=0.037) and versus atenolol in the LIFE study (hazard ratio 0.57, p=0.019). Patients enrolled in the RENAAL study were at a higher risk of developing HF (hazard ratio for RENAAL vs LIFE diabetics 3.0, p&lt;0.0001). The significant, independent baseline risk factors for the development of HF in the RENAAL study were urinary albumin/creatinine ratio, age, peripheral vascular disease, the Cornell product, body mass index, and previous angina; in the LIFE study they were the Cornell product, previous myocardial infarction, peripheral vascular disease, baseline atrial fibrillation, alcohol use (inverse relation), and urinary albumin/creatinine ratio. The beneficial effect of losartan on the reduction of risk for hospitalization for new HF was demonstrated in patients who were at high renal and/or high cardiovascular risk.

Acute myocarditis mimicking acute myocardial infarction: a clinical nightmare with forensic implications.

Authors present the case of the sudden death of a 30-year-old man, 3 h since his hospitalization by the onset of aspecific chest pain. ECG findings revealed the presence of localized ST segment elevation in precordial leads (V1-V4) and DII-DII, and aVF mimicking acute antero-inferior myocardial infarction. A diagnosis of acute antero-inferior myocardial infarction was advanced and the patient introduced to thrombolytic therapy. Suddenly, on ECG monitor, conduction abnormalities were early recorded (ventricular extrasystole) followed by ventricular tachycardia degenerating in fatal ventricular fibrillation. An alleged medical malpractice was sued against the cardiologist. A complete immunohistochemical study was performed. Histologically, the heart presented massive interstitial lymphocytic infiltrate and focal myocytes necrosis. The diagnosis of acute lymphocytic myocarditis was established as the cause of death.

The role of exogenous carbon monoxide in the recovery of post-ischemic cardiac function in buffer perfused isolated rat hearts.

Isolated rat hearts were perfused for 10 min with oxygenated buffer and equilibrated with carbon monoxide (CO) of 0.001% and 0.01% before the induction of 30 min global ischemia followed by 120 min of reperfusion. These concentrations of CO significantly improved the post-ischemic recovery of coronary flow (CF), aortic flow (AF), and left ventricular developed pressure (LVDP). The improvement in recovery reflected in the reduction of infarct size and the incidence of reperfusion-induced ventricular fibrillation (VF). Thus, hearts subjected to 0.001% and 0.01% of CO exposure via the perfusion buffer, infarct size was reduced from the CO-free control value of 39% +/- 5% to 21% +/- 3% (*p&lt;0.05) and 18% +/- 4% (*p&lt;0.05), respectively. In the presence of 0.001% and 0.01% CO, the incidence of VF was also reduced from its control value of 92% to 17% (*p&lt;0.05) and 17% (*p&lt;0.05), respectively. Increasing the CO exposure to 0.1% in the buffer, all hearts showed VF combined with ventricular tachycardia or bradycardia and various rhythm disturbances indicating the direct toxic effects of CO on the myocardium. The results show that cardioprotective concentrations (0.01% and 0.001%) of exogenous CO related to an increase in cGMP levels and guanylate cyclase activities.

Suppression of AC railway power-line interference in ECG signals recorded by public access defibrillators.

Public access defibrillators (PADs) are now available for more efficient and rapid treatment of out-of-hospital sudden cardiac arrest. PADs are used normally by untrained people on the streets and in sports centers, airports, and other public areas. Therefore, automated detection of ventricular fibrillation, or its exclusion, is of high importance. A special case exists at railway stations, where electric power-line frequency interference is significant. Many countries, especially in Europe, use 16.7 Hz AC power, which introduces high level frequency-varying interference that may compromise fibrillation detection.</AbstractText>Moving signal averaging is often used for 50/60 Hz interference suppression if its effect on the ECG spectrum has little importance (no morphological analysis is performed). This approach may be also applied to the railway situation, if the interference frequency is continuously detected so as to synchronize the analog-to-digital conversion (ADC) for introducing variable inter-sample intervals. A better solution consists of rated ADC, software frequency measuring, internal irregular re-sampling according to the interference frequency, and a moving average over a constant sample number, followed by regular back re-sampling.</AbstractText>The proposed method leads to a total railway interference cancellation, together with suppression of inherent noise, while the peak amplitudes of some sharp complexes are reduced. This reduction has negligible effect on accurate fibrillation detection.</AbstractText>The method is developed in the MATLAB environment and represents a useful tool for real time railway interference suppression.</AbstractText>

Recurrence of atrial fibrillation after internal cardioversion of persistent atrial fibrillation: prognostic importance of electrophysiologic parameters.

The purpose of this study was to determine whether the extent of atrial electrical remodeling affects the recurrence of atrial fibrillation (AF) after cardioversion of persistent AF (PAF).</AbstractText>Internal atrial cardioversion was performed in 47 patients with PAF. The right atrial monophasic action potential duration (RA-MAPD) at pacing cycle lengths (PCLs) of 800-300 ms and P wave signal-averaged electrocardiogram were recorded after cardioversion. Bepridil (150-200 mg/day) and carvedilol (10 mg/day) were administered to all patients after cardioversion. Of the 47 patients, 20 had recurrent AF within 3 months. No relation was observed between age, left atrial dimension, left ventricular ejection fraction, and AF recurrence. The AF duration was significantly longer (p&lt;0.05) and RA-MAPD at PCLs of 800 to 300 ms were significantly shorter (p&lt;0.05) in patients with AF recurrence than in those without recurrence. The mean slope of the RA-MAPD for PCLs between 600 and 300 ms did not differ between the patients with and without AF recurrence. The filtered P-wave duration (FPD) was significantly longer in the patients with AF recurrence than in those without (p&lt;0.05). Multivariate analysis also showed that the RA-MAPD at a PCL of 300 ms and FPD were predictors of AF recurrence (RAMAPD: p=0.038; FPD: p=0.052).</AbstractText>These results suggest that electrical remodeling related to the repolarization and depolarization may be the main contributors to early AF recurrence after cardioversion under the administration of bepridil and carvedilol.</AbstractText>

The Cox maze procedure in mitral valve disease: predictors of recurrent atrial fibrillation.

The Cox maze procedure is the gold standard for ablation of atrial fibrillation in patients undergoing mitral valve surgery, and new approaches to atrial fibrillation ablation must be compared with it. Therefore, we sought to determine the time-related prevalence of atrial fibrillation and its risk factors after combined Cox maze and mitral valve surgery.</AbstractText>From November 1991 through January 2004, 263 patients (mean left atrial diameter, 5.8 +/- 1.2 cm) underwent combined mitral valve surgery (repair in 71%) and a cut-and-sew Cox maze procedure for atrial fibrillation (permanent, 74%; persistent, 7%; paroxysmal, 16%). Rhythm documented on 2367 postoperative electrocardiograms was used to estimate the prevalence of atrial fibrillation across time.</AbstractText>Hospital mortality was 1.9%. Postoperative atrial fibrillation prevalence peaked at 36% at 2 weeks, decreasing to 21% at 5 years. Risk factors for higher postoperative atrial fibrillation prevalence varied with time and included longer duration of preoperative atrial fibrillation (P = .003), larger left atrial diameter (P = .01), older age (P = .0002), and higher left ventricular mass index (P = .02).</AbstractText>In some patients undergoing mitral valve surgery and a Cox maze procedure, atrial fibrillation recurs over time, mandating close, long-term follow-up of heart rhythm. Earlier operation and left atrial size reduction should be considered to improve results in selected patients.</AbstractText>

The roles of chronic pressure and volume overload states in induction of arrhythmias: an animal model of physiologic sequelae after repair of tetralogy of Fallot.

Sudden death occurs in as many as 8% of patients after repair of tetralogy of Fallot and has been attributed to arrhythmias. The purpose of this study was to establish an animal model to evaluate the individual contribution of different physiologic sequelae after tetralogy of Fallot repair in the development of late-onset arrhythmias.</AbstractText>Forty-nine piglets were divided into 5 groups: (1) pulmonary artery band; (2) pulmonary valvotomy; (3) pulmonary artery band plus pulmonary valvotomy; (4) infundibular scar; and (5) age-matched control animals. Baseline and follow-up electrocardiograms were obtained and recorded, as well as changes in QRS duration. A total of 45 animals underwent hemodynamic evaluation and programmed electrical stimulation at 5.6 months postoperatively.</AbstractText>Sustained ventricular tachyarrhythmias (ventricular tachycardia/ventricular fibrillation) were induced in 31.1%, and atrial arrhythmias were induced in 33.3%. The pulmonary valvotomy group was 30 times more likely to evidence arrhythmias than control animals for sustained ventricular tachycardia/ventricular fibrillation, as well as atrial arrhythmias (P = .01). The pulmonary artery band group was 15 times more likely to evidence atrial arrhythmias than control animals (P = .02). Prolonged QRS duration was predictive of inducibility of both atrial arrhythmias (P &lt; .01) and sustained ventricular tachycardia/ventricular fibrillation (P = .01). Mean right atrial (P = .01) and capillary wedge (P = .01) pressures predicted atrial arrhythmia inducibility. Right ventricular end-diastolic pressure predicted atrial arrhythmia (P= .01) and sustained ventricular tachycardia/ventricular fibrillation inducibility (P = .05). Right ventricular systolic pressure did not predict inducibility of either atrial arrhythmias (P = .10) or sustained ventricular tachycardia/ventricular fibrillation (P = .94).</AbstractText>Chronic right ventricular volume overload resulted in an increased incidence of inducible ventricular and atrial arrhythmias.</AbstractText>

Effects of fasudil, a Rho-kinase inhibitor, on myocardial preconditioning in anesthetized rats.

The aim of this study was to examine the effects of fasudil, a Rho-kinase inhibitor, on ischemic preconditioning and carbachol preconditioning in anesthetized rats. The total number of ventricular ectopic beats was markedly augmented with fasudil at 0.3 mg/kg and depressed with fasudil at 10 mg/kg. Fasudil at 10 mg/kg also markedly decreased the ventricular tachycardia incidence. Ischemic preconditioning, induced by 5 min coronary artery occlusion and 5 min reperfusion, decreased the incidence of ventricular tachycardia and abolished the occurrence of ventricular fibrillation. The incidences of ventricular tachycardia and ventricular fibrillation in the fasudil (10 mg/kg) + ischemic preconditioning group were found to be similar to the ischemic preconditioning group. However, low doses of fasudil (0.3 and 1 mg/kg) appeared to prevent the antiarrhythmic effects of ischemic preconditioning. Carbachol (4 microg/kg/min for 5 min) induced marked reductions in mean arterial blood pressure, heart rate and abolished ventricular tachycardia. Marked reductions in ventricular ectopic beats and ventricular tachycardia were noted in the fasudil (10 mg/kg) + carbachol preconditioning group. Lactate levels were markedly reduced in the ischemic preconditioning group and this reduction was prominently inhibited with fasudil at 1 mg/kg. Ischemic preconditioning caused a marked decrease in plasma malondialdehyde levels. Fasudil (10 mg/kg), ischemic preconditioning and carbachol preconditioning each generated marked reductions in ischemic myocardial malondialdehyde levels. Decreases in infarct size were observed with fasudil (10 mg/kg) treatment, ischemic preconditioning and carbachol preconditioning when compared to control. These results suggest that low doses of fasudil (0.3 and 1 mg/kg) appeared to prevents the effects of ischemic preconditioning and carbachol preconditioning, but a high dose of fasudil (10 mg/kg) was able to produce cardioprotective effects on myocardium against arrhythmias, infarct size or biochemical parameters and mimic the effects of ischemic preconditioning in anesthetized rats.

Ambulatory monitoring of aborted sudden cardiac death related to hypertrophic cardiomyopathy.

A 47-year-old woman with obstructive hypertrophic cardiomyopathy presented with chest pain that had persisted despite treatment with verapamil and alpha-receptor antagonists. The patient had no other significant cardiac symptoms, no history of hypertension, and no familial predisposition to hypertrophic cardiomyopathy or sudden cardiac death. A loud (grade III/VI), dynamic, systolic ejection murmur was noted that could be heard diffusely over the precordium.</AbstractText>Radionuclide perfusion imaging, coronary angiography, intracoronary Doppler flow measurements, and ambulatory electrocardiographic monitoring.</AbstractText>Obstructive hypertrophic cardiomyopathy, myocardial ischemia and sudden cardiac arrest.</AbstractText>Surgical myectomy and cardioverter-defibrillator implantation.</AbstractText>

Sudden cardiac death in a young woman: tumor of the atrioventricular (AV) node or citalopram intoxication?

Atrioventricular (AV) node tumor is a very rare lesion of the cardiac conduction system. Clinically, it is associated with complete AV block and sudden cardiac death, often in apparently healthy young people. We report a case of a 24-year-old woman who developed ventricular fibrillation during sexual intercourse and died before admittance to the hospital. The woman had a medical history of depression and was treated with citalopram.At first, no macroscopic or microscopic pathologic changes were found. Toxicologic analysis showed a toxic level of citalopram in the blood. Further microscopic examination of the cardiac conduction system disclosed a tumor of the AV node. Immunohistochemical staining confirmed endodermal origin in accordance with the latest hypothesis of the pathogenesis of this tumor. It was concluded that this young woman died of cardiac arrhythmia due to the AV tumor and not from citalopram intoxication, as first suspected. This case emphasizes the importance of a microscopic examination of the cardiac conduction system in cases of sudden unexpected death, even in cases with a plausible cause and manner of death at first glance.

The mechanism of atrial antiarrhythmic action of RSD1235.

RSD1235 is a novel drug recently shown to convert AF rapidly and safely in patients.(1) Its mechanism of action has been investigated in a rat model of ischemic arrhythmia, along with changes in action potential (AP) morphology in isolated rat ventricular myocytes and effects on cloned channels.</AbstractText>Ischemic arrhythmias were inhibited with an ED50 of 1.5 micromol/kg/min, and repolarization times increased with non-significant effects on PR and QRS durations. AP prolongation was observed in rat myocytes at low doses, with plateau elevation and a reduction in the AP overshoot at higher doses. RSD1235 showed selectivity for voltage-gated K+ channels with IC50 values of 13 microM on hKv1.5 (1 Hz) versus 38 and 30 microM on Kv4.2 and Kv4.3, respectively, and 21 microM on hERG channels. RSD1235 did not block IK1 (IC50 &gt; 1 mM) nor ICa,L (IC50= 220 microM) at 1 Hz in guinea pig ventricular myocytes (n = 4-5). The drug displayed mild (IC50= 43 microM at 1 Hz) open-channel blockade of Nav1.5 with rapid recovery kinetics after rate reduction (10--&gt;1 Hz, 75% recovery with tau= 320 msec). Nav1.5 blocking potency increased with stimulus frequency from an IC50= 40 microM at 0.25 Hz, to an IC50= 9 microM at 20 Hz, and with depolarization increasing from 107 microM at -120 mV to 31 microM at -60 mV (1 Hz).</AbstractText>These data suggest that RSD1235's clinical selectivity and AF conversion efficacy result from block of potassium channels combined with frequency- and voltage-dependent block of INa.</AbstractText>

Evidence that activation following failed defibrillation is not caused by triggered activity.

Earliest postshock activation following failed defibrillation shocks slightly lower than the defibrillation threshold (DFT) in large animals appears to arise from a focus. We tested the hypothesis that these foci are caused by early or delayed afterdepolarizations (EADs or DADs) by performing epicardial electrical mapping and giving the EAD inhibitor pinacidil or the DAD inhibitor flunarizine to see if the foci were extinguished or altered in timing or location.</AbstractText>A sock containing 504 electrodes was placed over the entire ventricular epicardium of 12 open-chested pigs. After the DFT was determined and additional shocks given, pinacidil was administered to 6 pigs and flunarizine to 6 pigs. Then, the DFT was again determined and additional shocks were given. Pinacidil significantly shortened the effective refractory period (ERP) (162 +/- 16 vs 130 +/- 28 msec) and action potential duration (APD(90)) (179 +/- 6 vs 149 +/- 19 msec) and significantly increased the peak frequency of the power spectrum of a left ventricle (LV) electrode during ventricular fibrillation (VF) (9.3 +/- 0.6 vs 10.5 +/- 1.0 Hz), while flunarizine did not significantly alter the ERP (162 +/- 8 vs 167 +/- 18 msec) or APD(90) (187 +/- 12 vs 191 +/- 20) but significantly reduced the peak frequency (9.2 +/- 0.5 vs 7.5 +/- 1.0 Hz). These findings suggest the drugs had their expected electrophysiological effects. However, the DFT was not significantly changed by either drug. Following the same strength shock 10% below the predrug DFT, earliest postshock activation arose in a focal epicardial pattern from the anterior-apical LV both before and after the drugs. The time from the shock until the appearance of this activation was not significantly different before and after either drug.</AbstractText>The lack of change in DFT as well as the lack of change in the incidence, location, and timing of the postshock focus with sub-DFT strength shocks before and after pinacidil and flunarizine provide evidence that these foci are not caused by triggered activity.</AbstractText>

Dietary fish oil protects against stretch-induced vulnerability to atrial fibrillation in a rabbit model.

Dietary fish oil is thought to reduce sudden cardiac death by suppressing ventricular arrhythmias but little is known about its impact on atrial arrhythmias. We examined the effect of dietary fish oil on the rabbit model of stretch-induced vulnerability to atrial fibrillation (AF).</AbstractText>Six-week-old rabbits were fed standard rabbit pellets supplemented with 5% tuna fish oil (n = 6) or supplemented with 5% sunflower oil (n = 6) for 12 weeks. Six rabbits raised on the standard diet were used as controls. In Langendorff-perfused hearts intraatrial pressures were increased in a stepwise manner and rapid burst pacing applied to induce AF at increasing intraatrial pressures until AF was sustained (&gt;1 minute). Atrial refractory periods were recorded at each pressure. Increased atrial pressure resulted in a reduction in atrial refractory period and a propensity for induction of sustained AF. Higher pressures were needed to induce and sustain AF in the fish oil group compared with the sunflower oil and control groups. The stretch-induced drop in refractory period was also less marked in the fish oil group. Red blood cell, atrial, and ventricular omega-3 fatty acid levels were significantly higher in the fish oil group. The ratio of atrial n-6/n-3 polyunsaturated fatty acids was 13 +/- 0.9 with sunflower oil and 1.5 +/- 0.01 with fish oil (P &lt; 0.001).</AbstractText>Incorporation of dietary omega-3 fatty acids into atrial tissue reduces stretch-induced susceptibility to AF.</AbstractText>

The impact of cardiac resynchronization therapy on ventricular tachycardia/fibrillation: an analysis from the combined Contak-CD and InSync-ICD studies.

To determine the potential influence of cardiac resynchronization therapy (CRT) on the frequency and types of ventricular arrhythmia (VA) in patients with an indication for the implantable cardioverter-defibrillator (ICD), we performed a retrospective electrogram (EGM) analysis of stored VA events from the two largest CRT-ICD trials.</AbstractText>Previous reports suggest that CRT might promote polymorphic VT (PVT), while a beneficial effect of CRT on ventricular function might reduce the frequency of monomorphic VT (MVT). Theoretically, a balanced effect produces no change in overall VA.</AbstractText>We analyzed stored EGMs from patients in the Contak-CD and Insync-ICD studies receiving appropriate therapy for VA. EGM inspection distinguishes MVT and PVT using morphologic criteria rather than cycle length classification alone.</AbstractText>Of 1,041 subjects entering the two trials, 880 were randomized CRT (N = 439) or control (N = 441). We were able to analyze 840 EGMs in 150 patients with VA, including 678 MVT episodes and 162 PVT episodes. These events were distributed among 68 patients with active CRT (390 MVT vs 111 PVT) and 82 patients assigned to control (288 MVT compared to 51 PVT). The apparent increase in PVT episodes in the CRT group is not significant and can be explained by a disproportionate number of episodes in a few patients. We were unable to identify clinical variables predictive of PVT during CRT.</AbstractText>CRT is not associated with a measurable increase in the incidence of PVT, or in a reduction in MVT in the combined InSync-ICD and Contak-CD populations.</AbstractText>

Left ventricular-based cardiac stimulation post AV nodal ablation evaluation (the PAVE study).

Chronic right ventricular pacing has been reported to promote cardiac dyssynchrony. The PAVE trial prospectively compared chronic biventricular pacing to right ventricular pacing in patients undergoing ablation of the AV node for management of atrial fibrillation with rapid ventricular rates.</AbstractText>One hundred and eighty-four patients requiring AV node ablation were randomized to receive a biventricular pacing system (n = 103) or a right ventricular pacing system (n = 81). The study endpoints were change in the 6-minute hallway walk test, quality of life, and left ventricular ejection fraction. Patient characteristics were similar (64% male; age: 69 +/- 10 years, ejection fraction: 0.46 +/- 0.16; 83%, NYHA Class II or III). At 6 months postablation, patients treated with cardiac resynchronization had a significant improvement in 6-minute walk distance, (31%) above baseline (82.9 +/- 94.7 m), compared to patients receiving right ventricular pacing, (24%) above baseline (61.2 +/- 90.0 m) (P = 0.04). There were no significant differences in the quality-of-life parameters. At 6 months postablation, the ejection fraction in the biventricular group (0.46 +/- 0.13) was significantly greater in comparison to patients receiving right ventricular pacing (0.41 +/- 0.13, P = 0.03). Patients with an ejection fraction &lt;or=45% or with NYHA Class II/III symptoms receiving a biventricular pacemaker appear to have a greater improvement in 6-minute walk distance compared to patients with normal systolic function or Class I symptoms.</AbstractText>For patients undergoing AV node ablation for atrial fibrillation, biventricular pacing provides a significant improvement in the 6-minute hallway walk test and ejection fraction compared to right ventricular pacing. These beneficial effects of cardiac resynchronization appear to be greater in patients with impaired systolic function or with symptomatic heart failure.</AbstractText>

Short QT syndrome.

The QT interval on an electrocardiogram signifies the time required for the heart to repolarize after depolarization. It has long been appreciated that a long QT interval predisposes patients to life-threatening ventricular arrhythmia. Short QT syndrome is a newly described disease characterized by a shortened QT interval and by episodes of syncope, paroxysmal atrial fibrillation or life-threatening cardiac arrhythmias. The syndrome usually affects young and healthy people with no structural heart disease and may be present in sporadic cases as well as in families. Our understanding of a new disease has rarely benefitted so quickly from research in genetics, molecular biology and biophysics. It was first described in 2000 in a handful of patients, and since then 3 different genes associated with the disease and the biophysical basis have been described, and therapy has been made available. Here we review the current understanding of the pathophysiology, clinical presentation and treatment of short QT syndrome.

Atrial fibrillation in patients hospitalized for congestive heart failure: the same prognostic influence independently of left ventricular systolic function?

Atrial fibrillation (AF) was described to be associated with an adverse prognosis in several studies of heart failure (HF). However, it is not clear whether it directly increased mortality or is only a marker for severity of HF.</AbstractText>To determine the influence of AF on mortality of HF patients distinguishing between patients with preserved and deteriorated systolic function (SF).</AbstractText>1636 patients who, between 1991 and 2002 had been hospitalized in a Cardiology Service for HF, were studied. Survival (SV) data (mean follow-up time: 3.14 years) has shown that there was no difference in SV between patients with (540 patients of the whole group) and without AF in the group with preserved SF (presented in 38.7% of cases), however, in the group of patients with deteriorated SF (AF presented in 31.0% of cases), SV time was significantly (p=0.01) shorter among patients with AF, this association being independent of age, sex, aetiology, risk factors, clinical signs and pharmacological treatment; relative risk: 1.831(1.120-2.994).</AbstractText>AF is more prevalent among HF patients with preserved SF than among those with deteriorated SF, but only increases the risk of death among the latter.</AbstractText>

Ventricular fibrillation following removal of temporary epicardial pacemaking wires.

Temporary wires are routinely sutured to both the atrial and ventricular epimyocardium after open heart surgery. Despite their rarity, complications related to removal of such pacemaking wires may cause life threatening situations. We describe here a patient who developed ventricular fibrillation immediately after removal of temporary epicardial pacemaking wires.

[Perioperative management of patients with Brugada syndrome].

In 1992, Brugada et al. first reported eight cases of ventricular fibrillation, in which ST-segment abnormalities in leads V1 through V3 along with T-wave inversion, and complete or incomplete right bundle branch block were observed on the standard 12-leads ECG. Since then, this syndrome has been widely recognized as one of important diseases that can produce sudden death in middle aged healthy males. The ECG morphology of Brugada syndrome is believed to be caused by either an accentuation of the notch in the early phase of the action potential or loss of the action potential dome in the epicardium. Mechanisms of ventricular fibrillation in this syndrome are still unclear, but thought to be phase II re-entry caused by dispersion of the action potentials. It has been shown that mutations of the human cardiac Na+ channel gene (SCN5A) underlie multiple cardiac diseases including Brugada syndrome. In fact, single amino acid substitution within the SCN5A coding region can evoke a cardiac rhythm behavior. In this review, we will focus on recent progress of basic and clinical research of Brugada syndrome and perioperative management of this syndrome.

Intrapericardial cisplatin administration after pericardiocentesis in patients with lung adenocarcinoma and malignant cardiac tamponade.

Patients with lung adenocarcinoma often suffer from metastatic pericardial effusion that may eventually cause cardiac tamponade. Recurrence of pericardial effusion is frequent after pericardial drainage and therapy for the prevention of fluid reaccumulation is still controversial. We evaluated the safety and effectiveness of the intrapericardial infusion of cisplatin, a substance with antineoplastic and sclerosing properties, after pericardiocentesis in patients with lung adenocarcinoma and malignant cardiac tamponade.</AbstractText>Twenty-five patients (19 males and 6 females, median age 55 years) with lung adenocarcinoma confirmed by cytological examination and cardiac tamponade were studied. All patients underwent subxiphoid pericardiocentesis through catheter insertion, under electrocardiographic, echocardiographic and haemodynamic guidance. After the malignant aetiology of the pericardial effusion had been confirmed by cytological examination, cisplatin was instilled (10 mg in 20 ml normal saline) into the pericardial cavity during three consecutive days. Clinical and echocardiographic evaluation was performed every month thereafter.</AbstractText>Pericardial fluid of 350-1700 ml was removed (median 750 ml) and was haemorrhagic in 80% of the cases. Paroxysmal atrial fibrillation was detected in three patients (12%) and non-sustained ventricular tachycardia in two (8%). None of the patients had hypotension or retrosternal pain. One patient suffered from significant pericardial effusion reaccumulation (4%). Laboratory findings were not influenced by systemic drug absorption in any patient. Transthoracic echocardiographic study revealed pericardial thickening without physiology of constriction in 4 patients (16%). After pericardiocentesis, the mean survival period overall was 4.5 months (range 3-92 weeks), and mortality was attributed to widespread disease (respiratory failure).</AbstractText>Intrapericardial administration of cisplatin is safe and effective in preventing the reaccumulation of malignant pericardial effusion in the majority of patients with lung adenocarcinoma.</AbstractText>

Mitral valve repair versus replacement for isolated non-ischemic mitral regurgitation in patients with preoperative left ventricular dysfunction. A long-term follow-up echocardiography study.

The aim of this study was to evaluate LV function, by means of echocardiography, after mitral valve repair (MVr) or mitral valve replacement (MVR) in patients (pts) with chronic degenerative mitral regurgitation (MR) and depressed LV systolic function during a 6-years follow-up (FU) period.</AbstractText>Forty-five pts with moderately severe or severe MR and preoperative EF&lt;or=50% were divided into 2 groups: MVr group (27 pts, 19 men-8 women, aged 62+/-10 years) and MVR group (18 pts, 8 men-10 women, aged 60+/-12 years). The cause of MR was myxomatous mitral valve disease (MVr/MVR: 16/8), endocarditis (0/4) and degenerative mitral valves with ruptured chordae tendineae (11/6). All pts underwent transthoracic echocardiography preoperatively, postoperatively and annually during the FU period (6+/-3 years).</AbstractText>In MVr group, 5 pts died, 5 were lost to FU and 2 pts underwent MVR due to MVr failure. In MVR group, 6 pts died, 3 were lost to FU and 1 was re-operated due to prosthetic valve endocarditis. Atrial fibrillation was similar between the 2 groups. MVr pts demonstrated significant LVEDD decrease postoperatively which was persistent during FU (p&lt;0.05). LVESD also decreased (p&lt;0.05), VTI improved (p&lt;0.05), while FS and EF showed a trend to improve. In MVR pts, LVEDD was decreased (p&lt;0.05) but increased during FU (p&lt;0.05) and LVESD remained high, resulting in a decrease of FS and EF (p&lt;0.05). VTI remained unchanged (p=NS).</AbstractText>MVr in pts with non-ischemic MR and preoperative LV dysfunction achieves better preservation of LV systolic indices than MVR, probably due to preservation of the subvalvular apparatus and LV geometry.</AbstractText>

Hospital discharge diagnoses of ventricular arrhythmias and cardiac arrest were useful for epidemiologic research.

We investigated the validity of hospital discharge diagnosis regarding ventricular arrhythmias and cardiac arrest.</AbstractText>We identified patients whose record in the PHARMO record linkage system database showed a code for ventricular or unspecified cardiac arrhythmias according to codes of the International Classification of Diseases, 9th revision, clinical modification (ICD-9-CM). The validity of ICD codes for ventricular arrhythmias and cardiac arrest (427.1, 427.4, 427.41, 427.42, 427.5, 427.69) and ICD codes for unspecified cardiac arrhythmias (427.2, 427.60, 427.8, 427.89, 427.9) was ascertained through manual review of hospital clinical records. The positive predictive value (PPV) was calculated, and differences between characteristics of true and false positives were evaluated.</AbstractText>The PPV of ICD codes for ventricular arrhythmias and cardiac arrest was 82% (95% confidence interval CI = 72-92). True positive results were associated with male gender (P = .09) and younger age (P = .05). Of the unspecified cardiac arrhythmias 10% (95% CI = 2-18) were identified as ventricular arrhythmias or cardiac arrest.</AbstractText>Hospitalizations for ventricular cardiac arrhythmias and cardiac arrest (coded according to ICD-9-CM as paroxysmal ventricular tachycardia, ventricular fibrillation, ventricular flutter, ventricular premature beats, or cardiac arrest) have a high PPV and are useful for selecting events in epidemiological studies on drug-induced arrhythmias.</AbstractText>

Economic impact of the reduced incidence of atrial fibrillation in patients with heart failure treated with enalapril.

Atrial fibrillation (AF) in the setting of heart failure (HF) is linked to embolic stroke and exacerbation of HF. The rate of new-onset AF in patients with left ventricular dysfunction and mild to moderate HF enrolled in the SoLVD trials was significantly lower with enalapril than with placebo (5.4% vs 24% over 2.9 years, P &lt; .0001). The objective of this study was to predict economic benefits over 5 and 10 years of reduced AF incidence in patients receiving enalapril for the treatment of HF from a Canadian third-party payer perspective.</AbstractText>Consequences of reduced incidence of AF in enalapril-treated patients were modeled using a Markov model. Patients were assigned to 1 health state: no AF, AF, poststroke, or death, and moved from one state to the other according to published incidence rates. It was assumed that most patients with AF would receive warfarin for stroke prevention. Resource use and costs were mostly retrieved from published Canadian studies.</AbstractText>Reduced incidence of AF resulted in savings of 382 dollars and 525 dollars per patient treated with enalapril over 5 and 10 years, respectively, which stemmed mainly from reduced AF hospitalization and less need for warfarin and amiodarone. Sensitivity analyses demonstrated that enalapril becomes more cost saving as the baseline risk for embolic stroke in patients with AF increases and the use of warfarin prophylaxis decreases.</AbstractText>Reduced incidence of AF with enalapril leads to significant clinical and economic advantages on top of the already well-established benefits of enalapril for patients with HF.</AbstractText>

The Italian Registry for hypertrophic cardiomyopathy: a nationwide survey.

National registries are advocated as instrumental to the solution of rarity-related problems for patients with hypertrophic cardiomyopathy (HCM), including limited access to advanced treatment options. Thus, an Italian Registry for HCM was created to assess the clinical profile and the level of care nationwide of patients with HCM.</AbstractText>Cardiology centers over the national territory were recruited to provide clinical data of all patients with HCM ever seen at each institution. The enrollment period was from May 2000 to May 2002.</AbstractText>The registry enrolled 1677 patients from 40 institutions. Most (69%) were followed at referral centers, whereas 31% were from community centers with intermediate-low patient flow. Patients diagnosed after routine medical examinations or familial screenings were 39%. Most patients were male (62%), in their fourth to sixth decade of life, and in New York Heart Association class I to II (89%); 24% had resting left ventricular obstruction and 18% had atrial fibrillation. During a 9.7-year average follow-up, cardiovascular mortality was 1%/y, mostly because of heart failure, with no significant change over the last 3 decades; sudden death was less common (0.4%/y). Only 4% of patients received a defibrillator; 14% of the 401 patients with LV outflow obstruction underwent invasive relief of obstruction; and &lt;1% were offered genetic analyses or counseling.</AbstractText>The Italian Registry represents the first comprehensive attempt to evaluate the clinical impact and management of HCM at a national level. Findings underscore the role of screening strategies for an early diagnosis and suggest limited use of the advanced therapeutic options for HCM.</AbstractText>

An algorithm for synchronization of in vivo electroporation with ECG.

The combined treatment of tumours in which delivery of a chemotherapeutic agent is followed by high voltage electroporation pulses has been termed electrochemotherapy. The electrochemotherapy of tumours located relatively close to the heart muscle can lead to fibrillation of the heart, especially if electroporation pulses are delivered in the vulnerable period of the heart or in coincidence with heart arrhythmias. We built an electroporation pulse delivery algorithm that enables safer use of electrochemotherapy. The algorithm is designed to deliver pulses outside the vulnerable period and to prevent pulses from being generated in the presence of heart arrhythmias. We evaluated the algorithm's performance using records of the Long-Term ST Database, thus simulating real-world conditions. The results of the evaluation, a sensitivity of 91.751%, a positive predictivity of 100.000% and a delivery error rate of 8.268% for electroporation pulse delivery (medians), suggest that the algorithm is accurate and appropriate for application in electrochemotherapy of tumours regardless of tumour location.

A quantitative analysis approach for cardiac arrhythmia classification using higher order spectral techniques.

Ventricular tachyarrhythmias, in particular ventricular fibrillation (VF), are the primary arrhythmic events in the majority of patients suffering from sudden cardiac death. Attention has focused upon these articular rhythms as it is recognized that prompt therapy can lead to a successful outcome. There has been considerable interest in analysis of the surface electrocardiogram (ECG) in VF centred on attempts to understand the pathophysiological processes occurring in sudden cardiac death, predicting the efficacy of therapy, and guiding the use of alternative or adjunct therapies to improve resuscitation success rates. Atrial fibrillation (AF) and ventricular tachycardia (VT) are other types of tachyarrhythmias that constitute a medical challenge. In this paper, a high order spectral analysis technique is suggested for quantitative analysis and classification of cardiac arrhythmias. The algorithm is based upon bispectral analysis techniques. The bispectrum is estimated using an autoregressive model, and the frequency support of the bispectrum is extracted as a quantitative measure to classify atrial and ventricular tachyarrhythmias. Results show a significant difference in the parameter values for different arrhythmias. Moreover, the bicoherency spectrum shows different bicoherency values for normal and tachycardia patients. In particular, the bicoherency indicates that phase coupling decreases as arrhythmia kicks in. The simplicity of the classification parameter and the obtained specificity and sensitivity of the classification scheme reveal the importance of higher order spectral analysis in the classification of life threatening arrhythmias. Further investigations and modification of the classification scheme could inherently improve the results of this technique and predict the instant of arrhythmia change.

The mitochondrial origin of postischemic arrhythmias.

Recovery of the mitochondrial inner membrane potential (DeltaPsi(m)) is a key determinant of postischemic functional recovery of the heart. Mitochondrial ROS-induced ROS release causes the collapse of DeltaPsi(m) and the destabilization of the action potential (AP) through a mechanism involving a mitochondrial inner membrane anion channel (IMAC) modulated by the mitochondrial benzodiazepine receptor (mBzR). Here, we test the hypothesis that this mechanism contributes to spatiotemporal heterogeneity of DeltaPsi(m) during ischemia-reperfusion (IR), thereby promoting abnormal electrical activation and arrhythmias in the whole heart. High-resolution optical AP mapping was performed in perfused guinea pig hearts subjected to 30 minutes of global ischemia followed by reperfusion. Typical electrophysiological responses, including progressive AP shortening followed by membrane inexcitablity in ischemia and ventricular fibrillation upon reperfusion, were observed in control hearts. These responses were reduced or eliminated by treatment with the mBzR antagonist 4'-chlorodiazepam (4'-Cl-DZP), which blocks depolarization of DeltaPsi(m). When applied throughout the IR protocol, 4'-Cl-DZP blunted AP shortening and prevented reperfusion arrhythmias. Inhibition of ventricular fibrillation was also achieved by bolus infusion of 4'-Cl-DZP just before reperfusion. Conversely, treatment with an agonist of the mBzR that promotes DeltaPsi(m) depolarization exacerbated IR-induced electrophysiological changes and failed to prevent arrhythmias. The effects of these compounds were consistent with their actions on IMAC and DeltaPsi(m). These findings directly link instability of DeltaPsi(m) to the heterogeneous electrophysiological substrate of the postischemic heart and highlight the mitochondrial membrane as a new therapeutic target for arrhythmia prevention in ischemic heart disease.

Usefulness of transoesophageal echocardiography before cardioversion in patients with atrial fibrillation and different anticoagulant regimens.

To evaluate the prevalence of atrial thrombi in patients with atrial fibrillation undergoing different anticoagulation regimens before cardioversion; to evaluate the usefulness of transoesophageal echocardiography (TOE) guided cardioversion to prevent thromboembolic complications; and to correlate the presence of atrial thrombi with clinical and echocardiographic data.</AbstractText>757 consecutive patients admitted as candidates for cardioversion of atrial fibrillation were enrolled in the study. They were divided into four groups: effective conventional oral anticoagulation, short term anticoagulation, ineffective oral anticoagulation or subtherapeutic anticoagulation, and effective oral anticoagulation with a duration of &lt; 3 weeks for various clinical reasons. All patients underwent TOE before cardioversion; in the presence of atrial thrombi or extreme left atrial echo contrast, cardioversion was postponed. The incidence of thromboembolic events was evaluated after cardioversion.</AbstractText>Atrial thrombi were detected in 48 of the 757 (6.3%) patients. No significant differences in the percentage of atrial thrombosis were found in the four study groups. Patients with atrial thrombosis were older and had a higher percentage of mitral prosthetic valves, lower left ventricular ejection fraction, more severe atrial spontaneous echo contrast, and lower Doppler left atrial appendage velocities. 648 patients were scheduled for cardioversion. Cardioversion was successful in 89% of patients without any major thromboembolic event.</AbstractText>The prevalence of atrial thrombosis before cardioversion despite different treatments with anticoagulants is about 7% and a TOE guided approach may prevent the risk of embolic events.</AbstractText>

Oxidative mediated lipid peroxidation recapitulates proarrhythmic effects on cardiac sodium channels.

Sudden cardiac death attributable to ventricular tachycardia/fibrillation (VF) remains a catastrophic outcome of myocardial ischemia and infarction. At the same time, conventional antagonist drugs targeting ion channels have yielded poor survival benefits. Although pharmacological and genetic models suggest an association between sodium (Na+) channel loss-of-function and sudden cardiac death, molecular mechanisms have not been identified that convincingly link ischemia to Na+ channel dysfunction and ventricular arrhythmias. Because ischemia can evoke the generation of reactive oxygen species, we explored the effect of oxidative stress on Na+ channel function. We show here that oxidative stress reduces Na+ channel availability. Both the general oxidant tert-butyl-hydroperoxide and a specific, highly reactive product of the isoprostane pathway of lipid peroxidation, E2-isoketal, potentiate inactivation of cardiac Na+ channels in human embryonic kidney (HEK)-293 cells and cultured atrial (HL-1) myocytes. Furthermore, E2-isoketals were generated in the epicardial border zone of the canine healing infarct, an arrhythmogenic focus where Na+ channels exhibit similar inactivation defects. In addition, we show synergistic functional effects of flecainide, a proarrhythmic Na+ channel blocker, and oxidative stress. These data suggest Na+ channel dysfunction evoked by lipid peroxidation is a candidate mechanism for ischemia-related conduction abnormalities and arrhythmias.

[Prognostic factors of survival in post-cardiopulmonary-cerebral resuscitation in general hospital].

To assess clinical and demographic characteristics of patients who had cardiopulmonary resuscitation and identify short- and long-term survival prognostic factors.</AbstractText>Four hundred and fifty-two (452) resuscitated patients in general hospitals from Salvador were prospectively assessed through bivariate and stratified analysis in associations between variables and survival curve for a nine-year evolution assessment.</AbstractText>Age ranged from 14 to 93 years old, mean of 54.11 years old. Male gender patients prevailed and half of them had at least a base disease. Cardiovascular disease was the responsible etiology in 50% of cases. Cardiac arrest was observed in 77% of cases and only 69% of patients were immediately resuscitated. Initial cardiac rhythm was not diagnosed in 59% of patients. Asystole was the most frequent rhythm (42%), followed by ventricular arrhythmia (35%). Immediate survival was 24% and hospital discharge survival 5%. Cardiac arrest etiology, initial cardiac rhythm diagnosis, ventricular fibrillation or tachycardia as arrest mechanism, pre-resuscitation estimated time lower than or equal to 15 minutes and resuscitation time lower than or equal to 5 minutes were recognized as short-term prognostic factors. Non-administration of epinephrine, being resuscitated in private hospital and resuscitation time lower than or equal to 15 minutes were nine-year evolution survival prognostic factors.</AbstractText>Data may help healthcare professionals decide when start or stop in-hospital resuscitation.</AbstractText>

[Hypovolemic shock during surgery caused by a rectus sheath hematoma].

Prophylactic treatment with low molecular weight heparins (LMWH) is currently widely used to prevent thromboembolic events. However, such treatment is not free of risk. Among the possible complications described is rectus sheath hematoma. We report the case of a patient undergoing surgery for a hypophysial adenoma approached by the transsphenoidal route. He received LMWH prophylaxis for thromboembolism and showed a tendency to hypotension during surgery. The patient's condition deteriorated to hypovolemic shock accompanied by episodes of atrial fibrillation with rapid ventricular response. With the transfusion of medications, blood products and plasma volume expanders, the patient was stabilized and surgery was completed. A computed tomography scan then revealed a hematoma occupying the greater part of the left anterior rectus muscle. With conservative wait-and-see treatment the abdominal symptoms disappeared and the hematoma gradually receded until fully resolved. Spontaneous rectus sheath hematoma is a rare condition. Presentation is quite nonspecific and computed tomography is needed for reaching a firm diagnosis. When a hematoma is large, the initial clinical picture may include hypovolemic shock, which may develop during surgery if the hematoma is not diagnosed early. Intraoperative management will be much more difficult than it would have been if diagnosis and treatment had taken place before the operation.

[Cardiac arrest management in outpatient clinics: integration between hospital emergency care and the 118 emergency system in the model of Turin ASL 3].

The incidence of sudden cardiac death ranges from 0.4 to 1.28 every 1000 inhabitants per year. Sudden cardiac death is responsible for about 10% of all deaths in Italy in 2000. It is unpredictable and is related to malignant ventricular arrhythmias that may be interrupted in more than 70% of cases. Survival rates generally do not exceed 5% in out-of-hospital cardiac arrest, but, as previously reported, early defibrillation may increase survival rate by 3 times. The Italian law of April 3, 2001, and its recent amendments authorized healthcare providers and trained lay rescuers to use automated external defibrillators either for in-hospital or out-of-hospital settings. We planned a program for early defibrillation in ASL 3 in four outpatient clinics where a transit of 300,000 patients was expected in 2004. Defibrillators were placed in wall-mounted boxes. Opening of these boxes enable an automatic calling to the 118 emergency service that is able to dispatch an advanced cardiac life support team to the pertinent outpatient clinic. The system of wall-mounted boxes automatically communicates by modem with a programmable rate, the state of repair and efficiency of the single boxes, in order to simplify the control of the whole system of defibrillators. This plan of Turin ASL 3 is innovative in the metropolitan area and emphasizes the central role of the 118 emergency system in the management of out-of-hospital cardiac arrest, even in hospital settings such as outpatient clinics with a high number of old users at higher risk of cardiac events. This plan with the availability of automatic calling of the 118 emergency service will be proposed to remaining local hospital utilities for their outpatient settings as well as to other public utilities such as general stores, drugstores, airports where a significant transit mat be expected. The plan will include a specific training for the use of automated external defibrillators by first responders.

Left atrial radiofrequency ablation during mitral valve surgery for continuous atrial fibrillation: a randomized controlled trial.

Although left atrial radiofrequency ablation (RFA) is increasingly used for the treatment of chronic atrial fibrillation during mitral valve surgery, its efficacy to restore sinus rhythm and any resulting benefits have not been examined in the context of an adequately powered randomized trial.</AbstractText>To determine whether intraoperative RFA of the left atrium increases the long-term restoration of sinus rhythm and improves exercise capacity.</AbstractText><AbstractText Label="DESIGN, SETTING, AND PATIENTS" NlmCategory="METHODS">Randomized, double-blind trial performed in a single UK tertiary referral center with enrollment between December 2001 and November 2003. A total of 101 patients referred for mitral valve surgery with at least 6 months' history of uninterrupted atrial fibrillation were assessed for eligibility; 97 were enrolled. Patients were followed up for 12 months.</AbstractText>Patients were randomly assigned to undergo mitral valve surgery and RFA of the left atrium (n = 49) or mitral valve surgery alone (controls; n = 48).</AbstractText>The primary outcome measure was presence of sinus rhythm at 12 months; secondary measures were patient functional status and exercise capacity (assessed by shuttle-walk test), left atrial contractility, and left atrial and left ventricular dimension and function and plasma levels of B-type natriuretic peptide.</AbstractText>At 12 months, sinus rhythm was present in 20 (44.4%) of 45 RFA patients and in 2 (4.5%) of 44 controls (rate ratio, 9.8; 95% CI, 2.4-86.3; P&lt;.001). Restoration of sinus rhythm in the RFA group was accompanied by a greater improvement in mean (SD) shuttle-walk distance compared with controls (+94 [102] m vs +48 [82] m; P = .003) and a greater reduction in the plasma level of B-type natriuretic peptide (-104 [87] fmol/mL vs -51 [82] fmol/mL; P = .03). Patients randomized to receive RFA had similar rates of postoperative complications and deaths as control patients.</AbstractText>Radiofrequency ablation of the left atrium during mitral valve surgery for continuous atrial fibrillation significantly increases the rate of sinus rhythm restoration 1 year postoperatively, improving patient exercise capacity. On the basis of its efficacy and safety, routine use of RFA of the left atrium during mitral valve surgery may be justified.</AbstractText>ClinicalTrials.gov Identifier: NCT00238706.</AbstractText>

Predictors of survival and hospital outcome of prehospital cardiac arrest in southern Taiwan.

Despite recent improvements in emergency care medicine, outcome for prehospital cardiac arrest patients remains poor in southern Taiwan due to lack of training and authorization of emergency medical technicians to perform advanced life support. The purpose of this study was to analyze the characteristics of these patients and to identify possible predictive factors for final hospital discharge.</AbstractText>We retrospectively reviewed the characteristics of 361 prehospital cardiac arrest patients (male:female, 226:135; median age, 69 years) undergoing cardiopulmonary resuscitation (CPR) on arrival at the emergency department (ED) between January 1, 2001 and December 31, 2003. Multivariate analysis was performed by fitting explanatory variables into logistic regression models with respect to the outcomes of admission and to hospital discharge.</AbstractText>The overall survival rate was 21.1% (n = 76) to hospital admission and 7.2% (26) to hospital discharge. About half (54%) of the 26 patients who survived had cardiac disease. Only 3 patients received CPR from a bystander, and 2 of them survived. None of the patients received electrical defibrillation before arriving at hospital because emergency personnel were not authorized to perform advanced cardiac life support (ACLS) in Southern Taiwan during the study period. Factors that predicted survival to hospital discharge included a short interval between the cardiac arrest and arrival at the ED, initial rhythm of ventricular tachycardia/ventricular fibrillation (VT/VF), lower atropine dose, higher level of hemoglobin, less multiple organ failure, and shorter duration of resuscitation in the ED. Nine of the 32 patients (28%) with VT/VF survived compared with 5 of 49 (10%) with pulseless electrical activity and only 12 of 231 (5%) with asystole. No patients who required resuscitation for longer than 20 minutes in the ED survived to hospital discharge.</AbstractText>The results of this study illustrate that patients with VT/VF have good potential for successful resuscitation. Prompt resuscitation and easy access for ACLS are the key factors for success. Survival rates are likely to improve if more lay people perform CPR and if emergency unit personnel are trained and allowed to perform ACLS.</AbstractText>