Myocardial contrast echocardiography has been used for determination of infarct size (IS) in experimental models. However, with intermittent harmonic imaging, IS seems to be underestimated immediately after reperfusion due to areas with preserved, yet dysfunctional, microvasculature. The use of exogenous vasodilators showed to be useful to unmask these infarcted areas with depressed coronary flow reserve. This study was undertaken to assess the value of adenosine for IS determination in an open-chest canine model of coronary occlusion and reperfusion, using real-time myocardial contrast echocardiography (RTMCE).-1·min-1. Post-mortem necrotic area was determined by triphenyl-tetrazolium chloride (TTC) staining.Nine dogs underwent 180 minutes of coronary occlusion followed by reperfusion. PESDA (Perfluorocarbon-Exposed Sonicated Dextrose Albumin) was used as contrast agent. IS was determined by RTMCE before and during adenosine infusion at a rate of 140 mcg·Kg2 and increased to 2.58 ± 1.53 cm2 during adenosine infusion (p = 0.004), with good correlation between measurements . The necrotic area determined by TTC was 2.29 ± 1.36 cm2 and showed no significant difference with IS determined by RTMCE before or during hyperemia. A slight better correlation between RTMCE and TTC measurements was observed during adenosine  then before it .IS determined by RTMCE was 1.98 ± 1.30 cmRTMCE can accurately determine IS in immediate period after acute myocardial infarction. Adenosine infusion results in a slight better detection of actual size of myocardial damage. IS can be determined by myocardial contrast echocardiography after a period of coronary ischemia and reperfusion, by exploiting the "no-reflow" state of necrotic tissue -4. In thRTMCE is a technique that uses very low mechanical energy and, thus, allows the observation of real-time myocardial perfusion as a result of reduced background-tissue interference. Therefore, it is possibly the ideal tool for the evaluation of dynamic changes that occur in coronary blood flow and simultaneous evaluation of myocardial function . This st-1 body weight), intubated and mechanically ventilated. Additional anesthesia was administered during the experiment as needed. A 7F catheter was positioned in the left carotid artery for monitoring systemic arterial pressure, connected to a Biopac Systems device , and another 7F catheter was introduced into the jugular vein for drug infusions and volemic control.The protocol was conformed to the American Heart Association Guidelines for Animal Research Use. Twelve mongrel dogs weighting 12 to 20 Kg were anesthetized with sodium pentobarbital  was then dissected free from the surrounding tissue, and, at the time of coronary occlusion, an occluder was placed around of it. A two millimeter transit-time ultrasound probe  was placed around the LAD, proximal to the occluder, and connected to a digital flowmeter for epicardial coronary flow measurements.Myocardial contrast echocardiography was performed with a real-time ultrasound system  equipped with a 4-2 MHz transducer. Images were acquired in the longitudinal apical view by using a water-filled latex interface between anterior epicardium and the transducer. Power Pulse Inversion imaging was adjusted before contrast injection to minimize the clutter artifact due to cardiac motion. Specific instrumentation settings included: mechanical index ranging from 0.09 to 0.12 , low dynamic range and maximal line density. After adjustment, all parameters, including depth, focal point and gain, were held constant for each experiment. Manually triggered, transient, high mechanical index imaging ("Flash" imaging) was deflagrated at peak contrast intensity to destroy microbubbles within the myocardium, exclude artifacts and allow the evaluation of myocardial replenishment , prepared in our laboratory according to previous description . Briefly-1·min-1, using a infusion pump.Baseline RTMCE was obtained when hemodynamic stability had been achieved. LAD was then totally occluded for 180 minutes, with confirmation of absent coronary flow by electromagnetic flowmeter with continuous monitoring of hemodynamics. The occluder was then withdrawn and, at 30 minutes of reperfusion, myocardial wall motion (WM) and perfusion was analysed using RTMCE once coronary flow had reached a constant rate. Image acquisition was performed before and after a four-minutes intravenous infusion of adenosine at a rate of 140 mcg·KgThe complete sequence of flash imaging with high energy followed by subsequent myocardial refilling was acquired and stored on VHS videotape and optical disk for off-line processing and analysis. Sequences were acquired at reperfusion and compared to baseline to identify perfusional abnormalities.IS was defined by RTMCE as the residual perfusional myocardial defect area after coronary reperfusion, before and during adenosine infusion, and compared to tissue staining . At the Blood pressure, heart rate and LAD flow were collected at baseline, at 180 minutes of occlusion, at 30 minutes of reperfusion and during adenosine. IS was determined by two observers blinded of tissue staining measurements in all dogs.-1) was infused in the right coronary artery and left main branch and, simultaneously, a 2% solution of 2.3.5-triphenyl-tetrazolium chloride (TTC) was injected into LAD, during 5 minutes. The heart was then sectioned longitudinally, passing through aortic valve and cardiac apex and incubated into TTC at 37°C for 30 minutes. This technique stains viable myocardium brick red and spares necrotic tissue. Regions that failed to demonstrate brick red staining, appearing pale yellow, were considered necrotic myocardium [After completion of the protocol, animals were euthanized and had their heart excised. The LAD was again occluded at the same site and cannulated immediately after occlusion. Ostium of the right coronary artery and the left main branch were also cannulated. Evans blue dye  was considered statistically significant.Continuous and normally distributed data were expressed as mean ± one standard deviation (SD) and qualitative data as proportions. Within-groups comparisons were performed by paired Student's Three dogs had ventricular fibrillation and were excluded from the study. The protocol was successfully performed in the remaining nine dogs (mean weight of 15.8 ± 2.3 Kg). Technically adequate contrast imaging was obtained in all animals.-1) the baseline LAD flow. At 30 minutes of reperfusion, LAD flow had already returned to baseline levels. Intravenous infusion of PESDA caused no significant changes in baseline hemodynamic values.Hemodynamic data are summarized in Table 2, and increased to 2.58 ± 1.53 cm2 during adenosine infusion (p = 0.004). Adenosine consistently resulted in a slightly greater area of IS  or during adenosine and TTC (p = 0.78). There was a strong correlation between RTMCE and TTC measurements both before  and during adenosine infusion , as demonstrated in Figure The necrotic myocardial area determined by TTC staining was 2.29 ± 1.36 cmTC p = 0.3 or duriMeasurements of IS evaluated by the two independent observers showed a good concordance. Before adenosine infusion, the interobserver variability, expressed by the relative mean error, was 2.7% whereas during adenosine infusion it was 9.4%.Although some studies have already evaluated the use of RTMCE for assessment of myocardial perfusion after acute myocardial infarction , the rolIt is well known that in the immediate period after acute infarction, myocardium within the reperfusion to the ischemic bed is variable. Irreversibly injured myocardium is generally associated with loss of microvascular integrity, which is proportional to the extension and severity of myocellular necrosis . HoweverOur findings are that the analysis of myocardial perfusion by RTMCE slightly underestimated the IS, while the addition of adenosine resulted in a better correlation with TTC. However, we would like to emphasize that correlation between RTMCE and TTC was good even before adenosine infusion. Some mechanisms should be considered when analyzing possible factors related to the better IS determination using RTMCE than previously related reports using intermittent imaging techniques . It is iMagnetic resonance imaging with gadolinium-based contrast was been demonstrated a precise method for determining IS and its transmurality ,18. MagnIS estimation has been demonstrated limited immediately after reperfusion because of reactive hyperemia that occurs shortly after reperfusion and abates within hours . PreviouThe assessment of IS by two-dimensional contrast echocardiography was performed using a single tomographic plane. Consequently, the measurements obtained by RTMCE and tissue staining represent an estimation of the true spatial extent of infarcted myocardium. However, since the aim of this study was a direct comparison between IS determined before and during adenosine with anatomical area, this issue is minimized. Of note, previous animal studies validated the good agreement between echocardiographic measurements and anatomic findings of risk area as well as IS using the methodology employed in this study ,23.Our results are based on visual assessment of perfusion defects and their measurements by planimetry. Although myocardial blood flow quantification can provide information about myocardial viability after reperfusional therapy, we considered that it was not necessary for the design of this study.A prompt definition of the efficacy of reperfusion therapy as well as the extent of its residual microvascular damage by a non-invasive method has important implications for the management of patients with acute myocardial infarction. Also, the presence of preserved microvascular flow in the post-reperfusion period is associated with a lower rate of fibrous scar and less ventricular remodeling ,24. Our The author(s) declare that they have no competing interests.PMMD and WMJ designed the study and wrote the manuscript. JMT and JCNS performed echocardiographic examinations and provided input into manuscript revisions. VDA performed histological analysis. ACPC, PLL and JAFR provided knowledge into the myocardial infarction experimental model and performed manuscript review, with important intellectual contents.


Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction.To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography.Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR). Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed.Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern . In acute phase, there were no significant differences in left ventricular end-diastolic volume and ejection fraction . However, left ventricular end-diastolic volume in Group B was significantly larger than that in Group A , and ejection fraction in Group B was significantly lower than that in Group A  at 6 months. PIR and coronary flow velocity reserve of Group A were higher than Group B .The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction. In patients with myocardial infarction (MI), the distinction between irreversible fibrotic scar and akinetic but viable myocardium has important clinical implications. Several imaging techniques have been used to detect myocardial viability. Coronary blood flow reserve (CFR) has been established as a useful method for assessing microvascular function -3. PreviKawamoto T et al. showed that coronary blood flow spectrum immediately after primary percutaneous transluminal coronary angioplasty (PTCA) by use of a Doppler guidewire reflected a greater degree of microvascular damage in the risk area, and was useful in predicting recovery of regional left ventricular (LV) function .The diastolic deceleration slope of coronary flow velocity is steeper in patients with substantial 'no reflow' phenomenon assessed by myocardial contrast echocardiography (MCE). Recently, Shintani et al revealed that patients with a shorter deceleration half time (DHT) of diastolic coronary flow velocity have a poorer functional outcome among patients with anterior AMI and that the transthoracic Doppler echocardiography (TTDE)-determined DHT is a useful predictor of myocardial viability after anterior AMI .The assessment of MCE with intracoronary or venous injection of ultrasound contrast agents composed of microbubbles has been shown to provide information on perfusion territories, collateral flow, infarct size, myocardial viability, and success of reperfusion therapy -12. ReceThe aim of this study was to compare the MCE results with myocardial viability evaluated by CFR two weeks after AMI and CF of LAD at acute phase measured with high-frequency TTDE echocardiography and evaluated MCE with HPDI, CFR and CF in predicting functional recovery and LV remodeling.This study included 30 patients  with the first anterior AMI. All patients underwent successful revascularization by PTCA and stent placement in the acute phase (within 6 hours after the onset of chest pain). Inclusion criteria were typical anginal chest pain lasting > 30 min and ST-segment elevation of > 0.2 mV in at least two contiguous electrocardiographic leads. And inclusion criteria were also echocardiographic images of sufficient quality to allow adequate visualization of all myocardial segments from the apical views and angiographically documented patency of the infarct-related artery (TIMI grade 3 flow) on coronary angiograms taken in the repeated study. Six patients were excluded from analysis because of inadequate image quality of echocardiograpic images and coronary flow by TTDE.Exclusion criteria were pregnancy, lactation, unstable angina and second or third degree atrioventricular block, bronchial asthma and systolic blood pressure < 90 mmHg. All patients gave written informed consent.Transthoracic 2-dimensional (2D) echocardiographic images were obtained with an ultrasound imaging system . MCE was performed two weeks after AMI. The contrast agent used for this study was Levovist™, which is composed of galactose (mean diameter 1.2 μm). MCE was performed by administration of Levovist at a dose of 300 mg/dl by injecting 3 ml/3 sec using by Medrad Pulser™ , followed by a 10 ml saline flushed. Contrast enhanced images using HPDI mode (scanhead transmit to receive frequency = 1.8:3.6 MHz) were acquired on intermittent mode at each pulse intervals of 4 cardiac cycles with the ultrasound transmission gated to the T wave of the electrocardiogram (i.e. end-systole). The dynamic range of this system is 40 dB. The mechanical index was set as high as possible to increase microbubble destruction. Ultrasound system gains were optimized at the beginning of the study and held constant for subsequent image acquisitions. The filter threshold was optimized to reduce the appearance of any color over the myocardium before contrast injection. The apical 4-chamber view was used to assess myocardial perfusion in all patients. We set the focus point at the mid-portion of the LV and kept constant for the quantitative analysis at baseline and during ATP stress. Images were stored on a 2.3 Gbytes MO disk.We examined MCE under conditions at initial baseline and during an infusion of ATP. The dosage of ATP was selected of 0.15 mg/kg/min. Levovist was pushed into the intravenous infusion at baseline imaging and during ATP infusion for stress imaging. Since peak hyperemia begins 2 minutes after the ATP infusion, image acquisition was initiated 2 minutes after the start of the infusion. Since only 2–2.5 minutes of maximal hyperemia was available for imaging, HPDI was performed only in the apical views by obtaining 3 to 5 beats gated to every fourth cardiac cycle.The analysis was performed off-line using QuantiCon software  for the quantification of contrast based ultrasound images. Regions-of-interest (ROIs) were placed in the basal septum, mid septum, apex and apical portion of the lateral segment. The ROIs can be individually repositioned in each frame to match the anatomy of the unaligned images. The information is displayed as the number of scatters that have moved in the power mode. Thus, intensity curves of the mean Doppler information in the ROIs can be plotted overtime using this software. Peak intensities of color pixels (dB) were then measured in 4 different segments of the LV. The peak intensity ratios of the risk area  to the control area (PIR) at rest and during hyperemia were calculated. The control region was set in the basal septum in this study Fig. .We performed Doppler measurements of LAD flow velocity by TTDE within 24 hours after successful recanalization. Doppler echocardiographic examinations were performed with an SONOS 5500 digital ultrasound system with a broadband high frequency (5-12MHz) transducer (S12) and a Logic 500 digital ultrasound system with a frequency of 8 MHz . The color gain was adjusted to provide optimal images. The acoustic window was around the midclavicular line in the fourth and fifth intercostal. The ultrasound beam was transmitted toward the heart to visualize coronary blood flow in the LAD by color Doppler echocardiography. With a sample volume positioned on the color signal in the LAD, Doppler spectral tracings of flow velocity in the LAD were recorded by fast Fourier transformation analysis. All studies were continuously recorded on 1/2-inch super-VHS videotape for off-line analysis.The digitized coronary blood flow velocity spectrum provided the following parameters: peak systolic velocity (PSV: cm/sec), mean diastolic velocity (MDV: cm/sec), peak diastolic velocity (PDV: cm/sec), and deceleration time of diastolic flow velocity (DDT: msec). Retrograde flow was calculated as a negative value Fig. .We measured CFR of LAD two weeks after AMI at the same time of MCE. At first, we recorded baseline spectral Doppler signals in the distal portion of the LAD. Then, ATP was administered for two minutes and spectral Doppler signals were recorded during hyperemic conditions. All patients had continuous heart rate and ECG monitoring. Blood pressure was recorded at baseline, every minute during ATP infusion and at recovery. One experienced investigator who was unaware of the other patient data analyzed each study. Measurements were performed off-line by tracing the contour of the spectral Doppler signal using the computer incorporated in the ultrasound system. Mean diastolic velocity (MDV) and peak diastolic velocity (PDV) were measured at baseline and peak hyperemic conditions. CFR was defined as the ratio of hyperemic to basal peak diastolic coronary flow velocity.Before CFR measurements by TTDE, we measured LV wall  at end diastole by two-dimensional echocardiography. LV volume measurements were performed according to the recommendation of the American Society of Echocardiography. Apical two- and four-chamber views were obtained at baseline. End-diastolic and end-systolic LV volumes were computed by use of modified Simpson's method (method of disks). Furthermore, we assessed regional wall motion at rest on the basis of 16 segments of the LV as recommended by the American Society of Echocardiography.Left heart catheterization was performed by the femoral approach after local anesthesia induced with 0.5% lidocaine. Biplane left ventriculography was performed after injection of 4000 IU IV heparin to assess LV wall motion and to measure LV volume by the area-length method in the acute phase and 6 months after AMI. Selective coronary angiography was carried out by the Judkins technique after an intravenous injection of 3 mg of isosorbide dinitrate. Coronary angiography was analyzed quantitatively with the use of videodensitometric analysis performed with a commercially available system  in the manner previously reported .t-test, correlation between Doppler parameters and PIR was performed using linear regression analysis. Statistical significance was defined as p < 0.05.Data were expressed as a mean ± standard deviation. Continuous data between groups were compared by student Receiver operating characteristics (ROC) curve analysis was performed. Analyses were done with SPSS for Windows software.The clinical characteristics of the patients are summarized in Table There were no significant changes in the average heart rate , systolic blood pressure , and diastolic blood pressure  after intravenous ATP administration in all patients. ATP did not cause significant side effects in the study patients. Figure According to receiver operating characteristics curve analysis, the optimal cutoff value to identify myocardial viability by MCE was 861 msec for DDT  and 1.8 for CFR .FR in patients of Group A was significantly higher compared with CFR of Group B . In patients without a perfusion defect in the risk area by MCE, CFR was > 2.0 (Table 2Q = 0.566).DDT of Group A was significantly longer than that of Group B . CFR was correlated with DDT . PDV of group A was significantly smaller than that of Group B .According to present/absent post-infarct LV remodelling at follow-up, I divided two groups Table .In the acute phase, there were no significant differences of LVEDV and EF between the two groups.LVEDV of Group B was, however, significantly larger than that of Group A, and EF of Group B was significantly decreased as compared with EF of Group A 6 months after AMI Table .According to receiver operating characteristics curve analysis, the optimal cutoff value to predict wall motion recovery was 809 ms for DDT  and 2.0 for CFR  Fig. .In patients with reperfused anterior AMI, a shorter DDT of the LAD flow detected within 24 hrs after coronary reperfusion and CFR less than 1.75 were feasible predictors of poor functional outcome. These parameters correlated with the quantitative results by HPDI with intravenous MCE. TTDE provides a simple and promising means of noninvasive assessment of myocardial viability in patients with reperfused anterior AMI.Recent studies with intracoronary MCE have shown that about one fourth to one third of patients with AMI treated with primary PTCA have an inadequate tissue perfusion (no-reflow phenomenon) despite angiographically successful coronary recanalization . CharactIn patients with MCE no reflow, the coronary microvasculature was profoundly damaged and it seemed that microvascular impedance increased and the intramyocardial blood pool decreased. The coronary microvasculature would be diffusely obstructed in patients with MCE no reflow. Early systolic retrograde flow (ESRF) has been reported to be observed frequently in patients with no reflow in case of AMI after successful recanalization and was explained by an occluded coronary microvasculature.Kawamoto et al. showed that the degree of reduced systolic antegrade flow or the deceleration time of diastolic flow reflected the degree of microvasculature damage and was predictive of residual myocardial viability . They reRecently, Wakatsuki et al. revealed that the coronary flow velocity pattern measured immediately after successful primary stenting is predictive of the recovery of regional and global LV function in patients with AMI . The chaIn our study, there were 6 patients with early systolic retrograde flow. They had no myocardial perfusion in infarcted area by HPDI and revealed poor CFR. LV wall motion in all these patients did not recover at follow-up. The obstruction of the microvasculature with subsequent high impedance results in the inability to squeeze blood forward into the venous circulation during systole. It is consequently pushed back to the epicardial coronary artery to produce early systolic retrograde flow. The reduced intramyocardial blood pool, which fills rapidly during diastole, has been used to explain the rapid decline of diastolic velocity.Recently, Lepper et al. reported that the coronary flow reserve immediately and 24 hr after PTCA for AMI relates to myocardial perfusion determined by MCE and LV function in four weeks . From ouThere were no reports that were compared coronary blood flow velocity pattern and CFR by TTDE with intravenous MCE by using HPDI. Our study revealed that DDT at acute phase correlated with microvascular integrity by HPDI and with CFR after two weeks. The quantitative analysis by HPDI revealed the degree of microvascular dysfunction. HPDI is a feasible technique for the detection of a myocardial perfusion defect in patients with coronary artery disease after a venous injection of contrast agent. Previous works, however, used qualitative analysis of the HPDI . In the We used Levovist, which is sensitive to microbubble destruction at diagnostic ultrasound frequencies . SeveralIn patients who had myocardial viability, the peak intensity of the risk area was 0.668 ± 0.178 dB at rest. In patients who had no myocardial viability in the risk area, the curves of intensity showed no increase and peak intensity was 0.248 ± 0.015 dB at rest. During ATP induced hyperemia, peak intensities were increased in the segments with preserved myocardial integrity. In the segments without preserved myocardial integrity, however, there was no change in peak intensities. We diagnosed quantitatively myocardial viability using by HPDI. HPDI is strictly dependent on microvascular integrity and PIR shows quantitatively the degree of microvascular damage. There were significant differences of LV function at follow-up between two groups. Our data may provide additional information from the point of coronary flow pattern.Our main findings were that the myocardial perfusion status assessed by HPDI at rest and during ATP stress corresponds closely to CFR and DDT of CF. CF at acute phase and CFR two weeks after AMI onset correspond to left ventricular remodelling at chronic phase.A previous study showed that, in patients with myocardial infarction, CFR is inversely correlated with the extent of myocardial infarction and directly correlated with the improvement in wall motion contractility during the recovery period ,6. A valThere were no reports that had been investigated the relationship between CFR and DDT of LAD. From our study, CFR correlated with DDT. CFR and DDT revealed the degree of microvascular damage in myocardium.The patients with MCE no reflow, which had no viability in the infarcted area by HPDI, showed poor functional outcomes and left ventricular remodeling. The detection of viability with HPDI and CFR were useful for predicting of LV remodeling.We compared the myocardial opacification obtained by HPDI with CFR and DDT of LAD in patients after PTCA for AMI. The machine settings used in this study relate to the best knowledge at the time of study initiation. Optimal echocardiographic machine settings for MCE are rapidly evolving and are dependent on the applied contrast agent. Thus, it is very challenging to set up and adhere to a study protocol in a field in which knowledge of how to use an evolving technology is improving very quickly.The differences in the shell structure as well as gas compositions of different microbubbles are likely to influence their efficacy for myocardial perfusion assessment by HPDI. Unfortunately, real-time perfusion imaging is not available on the instrument used in this study. Using real-time assessment of perfusion defects, we can diagnose both wall motion and myocardial perfusion at the same time .We could not perform MCE study immediately after the primary angioplasty. This analysis included only a limited number of patients.Coronary flow reserve is related to the microcirculatory status, which will be either indirectly affected by epicardial coronary stenosis or directly affected by a previous myocardial infarction and other related factors.The coronary flow pattern may be influenced by left ventricular pressure. But we didn't compare CFR and coronary flow pattern with the left ventricular pressure. Further study is needed to clarify this issue. Systolic reversal flow is a specific indication of the no reflow phenomenon, but it was sometimes difficult to record the complete Doppler spectral envelope throughout the entire cardiac cycle by TTDE because of the systolic heart motion.Coronary flow velocity patterns relate to myocardial perfusion determined by intravenous MCE and CFR by TTDE.Intravenous MCE and intermittent harmonic power Doppler imaging has the potential to noninvasively identify myocardial viability in patients with a previous anterior MI. Quantitative assessment of microvascular integrity corresponds to the evaluation of the microcirculation by CFR using transthoracic echocardiography.The assessment of microvascular damage by HPDI, CFR and CF corresponds to left ventricular remodeling.DDT and PIR were more useful in detecting functional recovery.AMI-acute myocardial infarctionMCE-myocardial contrast echocardiographyCFR-coronary blood flow reserveCF-coronary artery flow patternLV-left ventricularTTDE-transthoracic Doppler echocardiographyHPDI-harmonic power Doppler imagingPIR-peak intensity ratios of the risk area to the control areaLAD-left anterior descending arteryDDT-deceleration time of diastolic flow velocityThe author(s) declare that they have no competing interests.


Left ventricular free wall rupture occurs in up to 10% of the in-hospital deaths following myocardial infarction. It is mainly associated with posterolateral myocardial infarction and its antemortem diagnosis is rarely made. Contrast echocardiography has been increasingly used for the evaluation of myocardial perfusion in patients with acute myocardial infarction, with important prognostic implications. In this case, we reported its use for the detection of a mechanical complication following myocardial infarction.A 50-year-old man with acute myocardial infarction in the lateral wall underwent myocardial contrast echocardiography for the evaluation of myocardial perfusion in the third day post-infarction. A perfusion defect was detected in lateral and inferior walls as well as the presence of contrast extrusion from the left ventricular cavity into the myocardium, forming a serpiginous duct extending from the endocardium to the epicardial region of the lateral wall, without communication with the pericardial space. Magnetic resonance imaging confirmed the diagnosis of impending rupture of the left ventricular free wall. While waiting for cardiac surgery, patient presented with cardiogenic shock and died. Anatomopathological findings were consistent with acute myocardial infarction in the lateral wall and a left ventricular free wall rupture at the infarct site.This case illustrates the early diagnosis of left ventricular free wall rupture by contrast echocardiography. Due to its ability to be performed at bedside this modality of imaging has the potential to identify this catastrophic condition in patients with acute myocardial infarction and help to treat these patients with emergent surgery. Left ventricular free wall rupture occurs in up to 10% of the in-hospital deaths following acute myocardial infarction (AMI), usually between 3 to 6 days after the infarction. It typically involves the anterior or lateral wall, in the terminal region of the left anterior descending coronary artery distribution. It is associated with transmural infarctions involving at least 20% of the left ventricle, and it rarely occurs in areas with good collateral blood supply [A 50-year-old man with history of systemic hypertension and cigarette smoking presented to the emergency room with epigastric pain that had begun two days earlier. Physical examination was unremarkable. Initial twelve-lead electrocardiogram displayed a 0.5 mm ST segment depression in leads V3 to V5, while cardiac markers showed elevated creatine kinase mass (32.8 ng/ml) and cardiac troponin (67.2 ng/ml). A diagnosis of a non-Q AMI was made. Because epigastric pain became worst, a new electrocardiogram was undertaken, revealing an 1 mm ST segment elevation in leads V2 to V5. Coronary angiography was then performed, which revealed 80% obstruction in left descendent anterior coronary artery, 90% obstruction in first diagonalis, 90% obstruction in right coronary artery and 90% obstruction in the second marginal branch of the circumflex coronary artery, with thrombus. Percutaneous transluminal coronary angioplasty was performed in this artery and resulted in TIMI flow II.In the third day post infarction, the patient underwent a transthoracic echocardiogram for the evaluation of left ventricular systolic function. The patient was asymptomatic, blood pressure was 120 × 80 mm Hg, and there were no signs of hemodynamic instability. Transthoracic echocardiogram disclosed mild left ventricular hypertrophy, a moderately depressed left ventricular systolic function due to lateral wall akinesia and severe hypokinesia of the inferior and posterior walls, and a small pericardial effusion. The lateral wall was thin but no signs of impeding left ventricular rupture was detected by two-dimensional imaging. The patient gave informed consent to participate in a research protocol to assess post AMI perfusion by myocardial contrast echocardiography.9 microbubbles/ml and mean size of 4.6 ± 0.2 microns [Myocardial contrast echocardiography was performed in the third day post-infarction with a commercially available system  equipped with a broadband 1–3 MHz) transducer (S3) and power modulation imaging, which is a pulse cancellation technique that deploys multiple pulses per image line, alternating full- and half-amplitude pulses . The sys–3 MHz trThe current indication of contrast agents in echocardiography includes left ventricular opacification and endocardial border delineation . HoweverThe assessment of myocardial perfusion by contrast echocardiography has been performed by different techniques including high mechanical index triggered imaging, in which destruction of microbubbles is decreased by intermittent imaging triggered with cardiac cycles, and real-time imaging . Real-tiContrast echocardiography seems to be an alternative non-invasive method for the early diagnosis of left ventricular free wall rupture. Due to its ability to be performed at bedside, this modality of imaging has the potential to identify this catastrophic condition following acute myocardial infarction and help to treat these patients with emergent surgery.The author(s) declare that they have no competing interests.MLZHT and MAC acquired the echocardiographic images and participated in the manuscript description. ACTR, JMT and JAFR prepared the manuscript and figures. WMJ participated in the design and review of the manuscript. All authors read and approved the final manuscript.


Diabetes is a major risk factor for cardiovascular disease. In particular, type 1 diabetes compromises the cardiac function of individuals at a relatively early age due to the protracted course of abnormal glucose homeostasis. The functional abnormalities of diabetic myocardium have been attributed to the pathological changes of diabetic cardiomyopathy.In this study, we used high field magnetic resonance imaging (MRI) to evaluate the left ventricular functional characteristics of streptozotocin treated diabetic Sprague-Dawley rats (8 weeks disease duration) in comparison with age/sex matched controls.Our analyses of EKG gated cardiac MRI scans of the left ventricle showed a 28% decrease in the end-diastolic volume and 10% increase in the end-systolic volume of diabetic hearts compared to controls. Mean stroke volume and ejection fraction in diabetic rats were decreased  compared to controls. Further, dV/dt changes were suggestive of phase sensitive differences in left ventricular kinetics across the cardiac cycle between diabetic and control rats.Thus, the MRI analyses of diabetic left ventricle suggest impairment of diastolic and systolic hemodynamics in this rat model of diabetic cardiomyopathy. Our studies also show that in vivo MRI could be used in the evaluation of cardiac dysfunction in this rat model of type 1 diabetes. Diabetic cardiomyopathy (DCM) is characterized by a cascade of myocardial changes that occurs in diabetes mellitus with fibrosis, hypertrophy and microcirculatory abnormalities. These cardiovascular complications compromise cardiac performance ultimately resulting in cardiac failure. A high prevalence of cardiac failure is seen in individuals with diabetic cardiovascular complications, with DCM as one of the key determinants . DCM is Magnetic resonance imaging (MRI) has proven to be a powerful and robust noninvasive imaging modality for structural and function evaluation of the rat heart . HoweverUnderstanding the course of pathological events in an appropriate model is the key for developing therapeutic strategies aimed at preventing the heart failure. In order to evaluate the cardiac performance in vivo we used MRI, a robust technique for resolving cardiac functional information and the reference standard for real time three dimensional visualization of myocardial structure ,10. In aAll procedures on rats were approved by the University of Kansas Medical Center Institutional Animal Care and Use Committee. Twelve male Sprague-Dawley rats aged 2 months with an initial body mass of approximately 250 g were used for the study. The rats were randomly assigned to control or diabetic groups (n = 6 per group). The rats in the diabetic group were given a single intraperitoneal dose of streptozotocin  in 10 mM sodium citrate buffer, pH 4.5. The control rats were injected with the same volume of vehicle. Diabetes was confirmed in the former group by measuring the non-fasting plasma glucose levels (≥ 300 mg/dL) two days following the injection. Body mass and plasma glucose levels were recorded once weekly. All rats were given unlimited access to chow and water for the entire duration of study.At the end of 8 weeks of diabetes, MRI scans were performed on rats using a 9.4 T horizontal bore scanner  and a 60 mm radio frequency volume coil while the rats were under 1.5% isoflurane anesthesia delivered via a nose cone in a mixture of air and oxygen (60% and 40% respectively). A cardiovascular physiological monitoring system  was used to monitor electrocardiogram (EKG), respiratory status, and body temperature. The physiological status of the rats was continuously monitored to ensure stable heart and respiratory rates during the imaging session. The rats were positioned in the magnet bore for imaging the left ventricle (LV). After confirmation of position with scout images, EKG gated gradient-echo based sequence was used to acquire cine images of cardiac cycle from a short axis view of the heart over 10 equally incremented intervals (labeled phase 1 through 10) with the following parameters: TR/TE = 25/2.44 ms, number of averages = 1, image matrix = 128 pixels × 128 pixels, field-of-view = 60 mm × 60 mm, frame rate = 10, number of slices = 1, and slice thickness = 2.0 mm. The image acquisition was repeated for a total of six times by moving the slice location to completely encompass the LV cavity from the base to the apex.2. The volumes from all six slices acquired during the same phase delay were integrated to obtain the volume of LV at the corresponding phase. These computations were repeated for all ten phases of the cardiac cycle. The phases corresponding to the largest and smallest LV volume were chosen to be representative of end-diastole and end-systole, respectively. The difference between the LV end-diastolic and the LV end-systolic volume was expressed as the stroke volume. The ratio of stroke volume to the end-diastolic volume was expressed as the ejection fraction (%).Images were analyzed using the Image J software  at 300% The LV wall volume was calculated from the phase 1 reconstruction of all six slices. Briefly, the LV wall was manually traced to obtain the pixel count within the region of interest, and the abovementioned pixel to area conversion factor was used to estimate the LV wall area. The wall volume for each slice was obtained from the product of slice thickness and estimated area . The sumC) levels were measured at the end of 8 weeks, one day prior to MRI scans. Plasma glucose levels were measured using AccuCheck Active  meter. HbA1C was determined using antibody based A1CNow meter . After MRI procedures, rats were euthanized with an overdose of sodium pentobarbital. The hearts were excised, washed in cold phosphate buffered saline, blotted, and weighed.Plasma glucose, body mass, and glycated hemoglobin  increase in the mean R-R interval of diabetic rats (242.5 ± 15.0 ms) compared to controls (216.7 ± 28.7 ms).Gating the data acquisition with strong R wave on the EKG signal resulted in the LV attaining maximum volume at phase 1 of the cardiac cycle in both control and diabetic rats. Hence this maximum was taken as the LV end-diastolic volume Fig. .The LV end-systolic volume was taken as the lowest cardiac cycle phase volume which occurred at phase 6 in both control and diabetic rats Fig. . The meaSubsequently, the mean stroke volume was 373.1 ± 8.8 μl in the control rats. Diabetic rats showed a significantly (P < 0.01) decreased value of 193.2 ± 4.5 μl. The mean ejection fraction remained significantly (P < 0.01) lower in diabetic group compared to the controls .The body mass normalized mean end-systolic and stroke volumes Table  were sigThe first derivatives of the LV volume with respect to time (dV/dt) during the cardiac cycle phase transitions are presented in Figure The STZ induced diabetic rats used in our experiments are reminiscent of a model of uncontrolled hyperglycemia due to absolute insulin deficiency. The later feature closely captures the metabolic condition of type 1 diabetes. The STZ rat model has been used to study both tissue pathology ,14 and tFunctional sensitivity of imaging modalities poses a major challenge for delineation of abnormalities of cardiac function in DCM . HoweverIn this study we utilized EKG gating to correlate the image acquisition with electromechanical end diastole to obtain functional information on the diabetic LV. The use of cine MRI to image the LV along the cardiac short axis provided excellent temporal resolution to delineate volume changes. The high contrast between the blood and endocardium allowed us to perform the planimetry on LV cavities from all images representing the ten phases of cardiac cycle. LV volume calculations showed a significant reduction of 28% in the mean end-diastolic volume of the diabetic group compared to controls. It has been suggested that the reduction of end-diastolic volume might be the undesirable consequence of an adaptive mechanism of stiff myocardium, in an effort to compensate for poor contractility by increased pressure during experimental cardiomyopathy . A stiffThe LV end-diastolic volume, stroke volume and ejection fraction displayed significant changes with diabetes in this study, in accordance with a previous report . HoweverThe derivatives of volume with respect to time (dV/dt) of the end-diastole to systolic transition and end-systole to diastolic transition were also significantly different between the diabetics and controls, substantiating the pathological changes involving both active (myocytes) and passive (matrix) components, respectively, in the dysfunction of diabetic LV ,3. The cAlthough our choice of division of the cardiac cycle into equi-duration phases in this study was arbitrary, thus facilitating the evaluation of LV volume with respect to time as a perfectly smooth function between phases, our results nevertheless agree to a substantial degree, with previous reports on normal and diabetic left ventricular function utilizing a slightly different methodology ,29.In this study we did not investigate right ventricular dynamics in diabetes. However convincing evidence suggests the impairment of right ventricular function as early as at 6 weeks of diabetes . In addiIn conclusion, the results from our investigations indicate that the functional manifestation of DCM in the STZ rat model of subchronic diabetes include early diastolic flow adaptation, systolic volume dysfunction and cardiac cycle phase dependent diminution of LV kinetics. Our study also demonstrates that in vivo MRI is capable of evaluating the cardiac dysfunction in this model of diabetes.DCM – Diabetic cardiomyopathyLV – Left ventricleMRI – Magnetic resonance imagingSTZ- StreptozotocinThe author(s) declare that they have no competing interests.RL carried out the diabetes induction procedures and rat maintenance, helped with data analysis, statistical procedures and drafting the manuscript. MB conceived of the MRI methods and helped with drafting the manuscript. BAH carried out the MRI procedures. MDA helped with data analysis and statistical procedures. IVS conceived of the study, participated in its design and coordination and helped to draft the manuscript. All authors read and approved the final manuscript.


Patients with left bundle branch block have a preserved right bundle branch conduction and the efficacy of left ventricular pacing could be explained with the fusion between artificial pulse delivered in the left lateral wall and the spontaneous right ventricular activation. Moreover, the efficacy of left ventricular pacing could be enhanced with an optimal timing between the spontaneous right ventricular activation and the left ventricular pulse.We evaluated a patient  with surgically corrected mitral regurgitation, sinus rhythm and left bundle branch block, heart failure (NYHA class III) despite medical therapy and low ejection fraction (25%): he was implanted with a biventricular device.We programmed ventricular pacing only through the left ventricular lead.We defined what we called electrocardiographic "fusion band" as follow: programming OFF the stimulator, we recorded the native electrocardiogram and measured, through the device, the intrinsic atrioventricular interval. Then, atrioventricular interval was progressively shortened by steps of 20 ms down to 100 ms. Twelve leads electrocardiogram was recorded at each step. The fusion band is the range of AV intervals at which surface electrocardiogram (mainly in V1 lead) presents an intermediate morphology between the native left bundle branch block (upper limit of the band) and the fully paced right bundle branch block (lower limit).The patient underwent echocardiographic examination at each atrioventricular interval chosen inside the fusion band. The following parameters were evaluated: ejection fraction, diastolic filling time, E wave deceleration time, aortic velocity time integral and myocardial performance index.All the echocardiographic parameters showed an improvement inside the fusion band, with a "plateau" behaviour. As the fusion band in this patient ranged from an atrioventricular delay of 200 ms to an atrioventricular delay of 120 ms, we chose an intermediate atrioventricular delay of 160 ms, presuming that this might guarantee the persistence of fusion even during any possible physiological  atrioventricular conduction variation.In this heart failure patient with left bundle branch block, tailoring of the atrioventricular interval resynchronized myocardial contraction with left ventricular pacing alone, utilizing a sensed right atrial activity and the surface electrocardiographic pattern. Patients with heart failure (HF), left ventricular dysfunction and left bundle branch block (LBBB) can be treated with cardiac resynchronization therapy (CRT) , which cPatients with LBBB generally have a preserved right bundle branch conduction and the efficacy of LV pacing can be explained with a fusion between the artificial pacing pulse delivered in the left lateral wall and the spontaneous right ventricular (RV) activation. Moreover, the efficacy of LV pacing could be enhanced with an optimal timing between the spontaneous RV activation and the LV pulse -15.Patients with sinus rhythm (SR), HF, left ventricular dysfunction and LBBB can provide a specific trigger for a good timing of ventricular stimulation, namely atrial activity, sensed or paced. In addition, as the atrioventricular (AV) interval can be programmed, the morphology of the QRS complex consequently varies, showing different degrees of fusion. In this context electrocardiogram (ECG) could be used as a marker reflecting the mechanical synchrony of the ventricles.This case report suggests that a properly timed fusion between the spontaneous RV activation and LV pacing corresponds to a good hemodynamic response of the heart and, therefore, the optimal timing of LV pacing could be determined simply by programming the AV interval on the basis of surface ECG pattern.We evaluated a patient  with surgically corrected mitral regurgitation, HF (NYHA class III), SR, LBBB and left ventricular dysfunction (ejection fraction 25%) despite optimal medical therapy; he was implanted with a biventricular device with independent ventricular outputs .We programmed ventricular pacing only through the LV lead. The device was tracked by the spontaneous atrial activity because of a preserved sinus node function.We defined what we called electrocardiographic "fusion band" as follows: the stimulator was first programmed OFF to assess the basal ECG of the patient and the intrinsic AV interval, namely the interval between atrial and RV sensing measured through the implanted device, was measured as well. Then, AV interval was progressively shortened by steps of 20 ms down to the lower limit of 80 ms. Twelve leads ECG was recorded at each step. The fusion band is the range of AV intervals at which surface ECG (mainly V1 lead) shows an intermediate morphology between the native LBBB pattern (upper limit of the band) and the fully paced right bundle brunch block (RBBB) pattern (lower limit).In order to investigate the "fusion band", we chose the following AV values: 200, 180, 160, 140, 120 ms , diastolic filling time (DFT), E wave deceleration time (DT), aortic velocity time integral (VTI) and myocardial performance index (MPI).All the echocardiographic parameters showed an improvement at each programmed AV interval with a "plateau" behavior. Within an AV interval of 200 and 120 ms we choose to program the AV interval at an intermediate value of 160 ms  AV conduction variation. Data from literature support this hypothesis  since LVThe improvement of every echocardiographic parameter inside the fusion band, as compared to the basal conditions, shows a plateau pattern. This has to be confirmed by a large-scale trial. We hypothesize that our method could be applied in the patients undergoing CRT, representing a simple and effective way to program the proper AV interval using only surface and intracardiac ECG analysis.If further studies will confirm this hypothesis, the programming of the devices would be simplified and made faster without any loss in effectiveness. Moreover this method saves the energy of RV pacing.The hypothesis of tailoring myocardial resynchronization with LV pacing alone from ECG criteria seems attractive and LV pacing could be proposed as a valid option in patients with sinus rhythm. This approach does not necessarily exclude the presence of RV lead as only patients with LBBB and stable sinus rhythm may do without RV pacing. In fact the possibility of new development of atrial fibrillation in HF patient must be considered: in this case biventricular pacing may be useful as during atrial fibrillation episodes fusion is not constantly present, due to the loss of the reference a trial trigger for LV pacing.Moreover, patients with indication to implantable defibrillators need RV lead for the appropriate sensing and defibrillation of the arrhythmias.Our HF patient with SR and LBBB showed an improvement of echocardiographic variables during the ECG "fusion band" obtained with LV pacing. This simple method, only based on ECG criteria, needs to be tested on a large group of patients.The author(s) declare that they have no competing interests.All the authors contributed to the definition of the proposed method. The paper has been written by L.G. The draft has been discussed by all the authors and the final version approved.


Though hemodialysis (HD) acutely improves cardiac function, the impact of background diseases like coronary artery disease (CAD) and Type 2 diabetes (DM) in the setting of end-stage renal disease (ESRD) is not known. Tissue velocity echocardiography (TVE) offers a fast choice to follow changes in myocardial function after HD in ESRD with concomitant DM and /or CAD.46 subjects  underwent standard and TVE prior to and shortly after HD. Besides standard Doppler variables, regional myocardial systolic and diastolic velocities, as well as systolic strain rate were post processed.Compared with pre-HD, post-HD body weight (kg) significantly decreased in all the three groups . Left ventricular end diastolic dimensions (mm) also decreased post- HD . Regional longitudinal peak systolic velocity in septum (cm/s) significantly increased post-HD in Group 1 while remained unchanged in the other two groups. Similar trends were noted in other left ventricular walls. When the myocardial velocities (cm/s) were computed globally, the improvement was seen only in Group 1 . Global early regional diastolic velocity (cm/s) improved in Group 1, remained unchanged in Group 2, while significantly decreased in Group 3. Global systolic strain rate (1/sec) increased in the first 2 Groups but remained unchanged  in Group 3.A single HD session improves LV function only in ESRD without coexistent DM and/or CAD. The present data suggest that not only dialysis-dependent changes in loading conditions but also co-existent background diseases determine the myocardial response to HD. Patients with Type 2 diabetes mellitus (DM) of long duration frequently suffer from end-stage renal disease (ESRD) and a great majority of them also have coexistent coronary artery disease (CAD) ,2. PatieThough it has been already demonstrated in patients undergoing HD that concomitant changes in the TVE variables are load dependant -9, it isTherefore, in this study, we have tested the hypothesis that longitudinal myocardial functions as assessed by TVE in response to HD are quantitatively different in differing clinical settings irrespective of similar degree of changes in loading conditions.The number of study subjects was 46. Patients with primary myocardial disease, significant pericardial disease, significant valvular disease or arrhythmias were excluded. Diagnoses of the illnesses were defined by standard criteria, medication and treatment history and from the hospital database. Diagnosis of CAD was on the basis of clinical history, findings of definite ECG changes of ischemia or previous myocardial infarction, echocardiographic findings of regional wall motion abnormality (n = 9) and those having angiographic evidence of significant coronary artery disease (n = 5). All biochemical analyses were done prior to HD, using a standard spectrophotometer.The Institutional Review Board of Bhagwan Mahavir Jain Heart Centre, Bangalore, India, approved the study protocol. All the study subjects gave their informed consent to participate.Echocardiography was performed using a VIVID 5 equipment  with a preinstalled Echopac 6.3.4 software program. A 2.5 MHz probe was used for image acquisition. The images were acquired in parasternal long- and short-axis and in apical 2-, 3-, and 4- chamber projections. LV dimensions and wall thicknesses were measured by M-mode in the parasternal long-axis views. Mitral inflow velocities were measured by conventional pulsed wave Doppler, by positioning the sample volume at the level of the tips of mitral leaflets in the apical 4-chamber views. The peak early (E) and late (A) diastolic velocities, and E/A ratio were measured. 2-D LV ejection fraction was measured by modified Simpson's approach. All 2-D and M-mode measurements were made according to the American Society of Echocardiography guidelines.-1 for post processing.Digitally stored cine loops during three consecutive heart cycles were analysed offline using Echopac 6.3.0 software . The LV long-axis regional function was assessed from the apical views from which four basal segments  were analysed. The cursor was placed in the basal segment so as to exclude the mitral annulus. A typical velocity profile could be obtained by positioning the sample volume in any of the basal segments. Peak systolic (PSV), early diastolic (E'), and late diastolic (A') myocardial velocities (cm/sec) were measured at the peaks of the respective waves on the myocardial velocity curves in the individual LV walls Figure . The corStrain represents deformation of an object  and is often expressed in percentage of change from end-diastolic dimension . PositivAll patients were on maintenance HD, done twice weekly. Duration of maintenance HD varied from 10 months to 7 years. Echocardiography was done within 60 minutes of pre- and postdialysis. Hemodialysis was performed using Fresemins-76 dialyser with dialysate flow rate of 500 ml/min. Sodium bicarbonate dialysis was done with dialysate flow of 500 ml/min and an average blood flow of 250 ml/min.Coronary angiographies were done using the Judkins technique. Significant stenosis was defined as >70 % intra-luminal obstruction either visually or quantitatively by coronary angiography.Data are expressed as mean ± SD. One-way ANOVA followed by Scheffe's test was performed to compare the differences among the three groups. Paired t test was performed to compare pre-and post-HD data within groups. A PC-based version of STATISTICA version 6.0 was used for data analyses. Intra-observer variation was similar to our previous study . All conOf the study subjects 31 were males and 15 females. The age (years) of the subjects respectively in the 3 groups were 40 ± 16, 57 ± 7, and 56 ± 9 (p < 0.05 for Group 1 vs. others). The study subjects were non-consecutively selected and divided as Group 1: ESRD due to primary renal disease (n = 17), Group 2: ESRD+DM (n = 15), and Group 3: ESRD+DM+CAD (n = 14). Patients with primary ESRD had polycystic kidney disease, IgA nephropathy, focal segmental glomerulosclerosis, or crescent glomerulonephritis. Remaining clinical characteristics of the study population are given in Table Table Table Table Following HD . A significant decrease in IVCT  after HD was observed in the latter group as well. E'/A' ratio was significantly lower in all the groups. Ejection, isovolumic relaxation, and filling times as well as LV displacement showed no significant differences.Measurement of IVCT, ET, IVRT and FT at pre- HD did not differ. ESRD group at post- HD showed global and regional decrease of ejection time (ET) in all the LV walls (data not shown). In the ESRD+DM group filling time was decreased only in septum, while in the ESRD+DM+CAD group there was global and regional decrease in ET in septum, lateral and anterior wall. Isovolumic relaxation time (IVRT) was however prolonged globally after HD  in the same group. On the other hand, isovolumic contraction time (IVCT) did not show any significant changes.LV filling pressures were assessed indirectly by calculating E/E' ratio at the septal and lateral annulus, pre- and post-HD. At pre-HD, there were no significant differences among the groups (data not shown). There was however a decrease in E/E' ratio at post-HD only in the ESRD group when measured separately and also when the average of the two walls was done .LV Global Tei index was significantly higher after HD (0.67 ± 0.22) than before  in Group 1 and in Group 3 , while remained unchanged in Group 2 .The principal findings of the study are: firstly, global left ventricular longitudinal systolic and diastolic myocardial velocities and systolic strain rate become higher in ESRD group post-HD; secondly, these variables are either unchanged or even become worse  declare that they have no competing interests.SCG performed all the echocardiographic investigations before as well as after hemodialysis and has been responsible for digital storage of the images and collected all the clinical data of the study subjects. SR did post-processing of the images along with SCG. LÅB was the scientific supervisor of the project and was responsible for final production of the manuscript. JN provided major scientific input into the study, reviewed the manuscript, drew Fig


Common diseases may be attributed to combinations of variant alleles, but there are few model systems where the interactions among such variants can be studied in controlled genetic crosses. While association studies are designed to detect common polymorphisms of moderate effect, new approaches are required to characterize the impact on disease of interactions among rare alleles.Drosophila melanogaster harbor rare polymorphisms of major effect (RAME) that predispose flies to a specific disease phenotype, age-dependent cardiac dysfunction. A screen of fifty inbred wild-type lines revealed a continuous spectrum of pacing-induced heart failure that generally increases in frequency with age. High-speed video analysis of the inbred lines with high rates of inducible heart failure indicates specific defects in cardiac function, including arrhythmias and contractile disorders (‘cardiomyopathies’). A combination of bulked segregant analysis and single feature polymorphism (SFP) detection localizes one of the cardiac susceptibility loci to the 97C interval on the fly genome.We show that wild populations of Drosophila, like humans, are predisposed to cardiac dysfunction. Identification of factors associated with these naturally occurring cardiac traits promises to provide important insights into the epidemiology of cardiac disease.Wild-type  Drosophila melanogaster has been widely adopted as a model organism for investigating the function of biomedically relevant genes Drosophila have focused on non-medical traits such as bristle number, wing shape, and aspects of life history including longevity and fecundity Drosophila. Application of external electrical stimulation elevates the normal heart rate for a short time, which may or may not result in heart failure (defined as fibrillation or arrest) at a rate that is characteristic for the genotype and age of the line of flies Pacing-induced cardiac dysfunction or failure is a rapid and efficient assay for detecting heart performance deficits in Such observations raise the possibility that polymorphism in a variety of genes might contribute to heart disease in natural populations Drosophila. We show that wild populations of D. melanogaster indeed carry major-effect cardiac failure-promoting alleles, and that these can be mapped by standard linkage methods.In this paper we describe one such strategy in the context of cardiac failure in Pacing-induced heart failure was performed as described in M-mode traces documenting the movement of the edges of the heart tube were performed as described in Low resolution mapping of the genetic region that explains a large proportion of the 1 week heart failure phenotype in the NC1 line was performed using Single Feature Polymorphism (SFP) analysis of Bulked Segregant pools of F2 flies from the cross with male tester yw flies. Raw array data is available online as the yw were selected as candidate SFPs, consistent with expectations given the high level of DNA sequence polymorphism in Drosophila. We then asked whether the F2 hybridization intensity for each probe was closer to the NC1 or yw intensity by computing the value of |yw–F2|/|yw–NC1|. A value of 0 implies that the yw genotype dominates the pool; 1 implies that NC1-derived alleles are prevalent; and 0.5 implies an equal mix. Absolute values greater than one (approximately 1% of the remaining probes) were excluded from further analysis as they do not make biological sense and presumably represent measurement error. We then plotted a sliding window along each chromosome arm of the average SFP score over 100 SFPs, as shown in yw. A dip in the profile in the middle of chromosome arm 2L may indicate a suppressor of heart failure in the NC1 line, but it was only significant in the second replicate.Probes with greater deviation than this between NC1 and p<0.0001, The incidence of pacing-induced heart failure was measured in one-week and five-week old flies from each of 50 highly inbred wild-type lines (30–100 flies per line) derived from a North Carolina peach orchard Ten lines with elevated heart failure rate and several with moderate or low failure rate were then analyzed in more detail for visible defects in heart performance. Adult hearts of up to 24 individuals of each line were exposed by dissection in oxygenated saline, allowing the heart beat to be captured with a high-speed camera at 100–200 frames per second see . ChangesIn dissected individuals of most lines and in laboratory ‘wildtype’ animals, the young adult heartbeat is highly rhythmic, with a constant ejection volume, systolic and diastolic (interbeat) interval length  strain, exhibit defects that are remarkably similar to those observed in NC1 homozygotes  detection in conjunction with Bulked Segregant Analysis (BSA) mosome 3 , consistbeat-VII locus, CG14249. Two sequence polymorphisms were detected, and for both of these, 25 clones derived from the NC1 strain allele, and 9 from the yw strain allele. This proportion, 73% NC1, is the same as that observed in the SFP analysis. Assuming incomplete penetrance for a purely dominant susceptibility allele in affected individuals, two thirds of the alleles would be expected to be from the NC1 parent. However, since NC1 homozygotes show slightly higher incidence of young adult heart failure than outcrossed heterozygotes Click here for additional data file.Text S2Repeatability of failure rate measurements. This word file shows the repeatability of the failure rate estimates on samples measured several months apart.(0.03 MB DOC)Click here for additional data file.Text S3Raw data for SFP analysis. This text file shows the raw probe intensities for each of six Affymetric SPF arrays. Probesets are listed by probe number, and data is shown in respective columns for NC01, F1 of NC70xyw, yw, NC70, and two replicate crosses of NC01xyw. Note that only the NC01 mapping is described in the manuscript.(11.63 MB TXT)Click here for additional data file.Video S1Normal heart beat. An MP4 video file showing a normal one week old beating heart.(1.95 MB MOV)Click here for additional data file.Video S2Abnormal heart beat. This is an MP4 video showing an example of an abnormal one week old heartbeat from line NC014.(0.65 MB MOV)Click here for additional data file.


The occurrence of variations in the spectrum of cardiovascular disease between different regions of the world and ethnic groups have been the subject of great interest. This study report the 24-h variation of myocardial infarction (MI) occurrence in patients recruited from CCU located in Argentina and Uruguay.A cohort of 1063 patients admitted to the CCU within 24 h of the onset of symptoms of an acute MI was examined. MI incidence along the day was computed in 1 h-intervals.A minimal MI incidence between 03:00 and 07:00 h and the occurrence of a first maximum between 08:00 and 12:00 h and a second maximum between 15:00 and 22:00 h were verified. The best fit curve was a 24 h cosinor  together with a symmetrical gaussian bell . A similar picture was observed for MI frequencies among different excluding subgroups . Proportion between cosinor and gaussian probabilities was maintained among most subgroups except for older patients who had more MI at the afternoon and patients with previous symptoms who were equally distributed among the morning and afternoon maxima.The results support the existence of two maxima (at morning and afternoon hours) in MI incidence in the Argentine and Uruguayan population. More than 50 years ago, Pell and D'Alonzo first demonstrated the existence of a peak in the morning hours in a study of acute myocardial infarction (MI) in a large industrial population . SubsequThe occurrence of variations in the spectrum of cardiovascular disease between different regions of the world and ethnic groups have been the subject of great interest -25. TherThis prompted us to examine the MI incidence along the day in the data obtained from GEMICA Study database, a prospective, multicenter, randomized, placebo-controlled, double blind, trial design to assess the effect of amiodarone on mortality after MI in an Argentine and Uruguayan population. The results of the GEMICA study were published elsewhere .GEMICA was launched in March 1994 and completed in July 1995 . PatientEvery patient who was hospitalized within the first 24 h after the onset of MI was screened. Diagnosis of infarction was based on the confirmation of two out of the three accepted criteria: i) prolonged (longer than 30 min) typical chest pain not responding to nitroglycerin, ii) sustained ST segment changes and/or appearance of new Q waves; iii) doubling of the blood creatine-phosphokinase normal value. Table The time each patient had suffered his/her MI was recorded up to within ± 0.5 h by interrogation of the patients or of their close relatives. MI incidence along the day was analyzed on total population and after dividing the population in several mutually excluding subgroups, as follows: (i) older than 70 years, 70 or less years; (ii) with or without previous symptoms; (iii) diabetics or non diabetics; (iv) Q wave- or non-Q wave-type MI; (v) anterior or inferior MI location.To quantify the time dependence of MI incidence, the 24 h period was divided into 1 h-intervals. Observed cases of MI onset in each time interval were expressed as percent incidence per hour (%/h) after normalizing the data by dividing the observed cases by N .Periodicity in occurrence of MI episodes along the day was assessed by comparing the distribution of MI incidence against a theoretical uniform distribution. The total population, as well as every subgroup, was separately analyzed. Differences in periodicity between each pair of mutually excluding subgroups were analyzed by using Chi-square test on 2 × 24 contingency tables.y(t) (%/h):Least squares regression analysis on MI incidence was performed for the total population and for every subgroup, using the following fitting function for the probability density y(t) = A + B * cos(ω24 * (t -tacrophase)) + (C/((2*Π)1/2 * σ)) * exp-((t-tm)2/(2*σ2))     [1]24 * (t -tacrophase)) is a cosinor function, i.e. a constant A (%/h) plus a harmonic oscillation around A with amplitude B (%/h), period 2 * Π/ω24 = 24 h and maximum at the acrophase tacrophase (hh:mm). By integrating over 24 h, the probability of cosinor component (%) resulted in A (%/h) times 24 h. The second component in [m (hh:mm) as mean value and σ (hh:mm) as SD. Gauss distribution was scaled to obtain C (%) for gaussian component.The first component, A + B * cos was set to accept a fit. The temporal constants tacrophase, tm, and σ were compared between mutually excluding subgroups, and also for every subgroup against total population. Differences between means (mi - mk) were analyzed under the assumption of means being independent and normally distributed. On each case, the adimentional variable z = (mi - mk)/(sei2 + sek2)1/2 was calculated, and the two-tailed p(z) value was obtained from a normal probability table.Being y(t) a sum of probability densities, a fitting procedure was imposed to reject any negative values for every component and to comply with the normalization constraint A * 24 h + C = 100%. Fitted constants were expressed as mean ± SEM. Goodness of fit was checked through the correlation coefficient Total probabilities for cosinor and gaussian components were not independent values. In consequence, differences between A * 24 h and C were analyzed for every subgroup, and also in the total population, by comparison against the half probability value 0.5 . A test of differences between two means modified for one-tailed p(z), was used. Differences were considered non-significant if p ≥ 0.05.y(t) superimposed to the observed hourly MI percentage. Inspection of data indicates minimal MI incidence between 03:00 and 07:00 h and the occurrence of a first peak between 08:00 and 12:00 h and a second peak between 15:00 and 22:00 h. This second peak occurred about 12 h after the minimal MI incidence; thus, a 24 h cosinor fitting was consistent with this observation. In addition, the morning maximum (between 08:00 and 12:00 h) resembles a symmetrical bell located over the rising flank of the cosinor curve; therefore, a gaussian component was added to the fitting function.The group of 1063 patients was analyzed as a total population and after division in excluding subgroups as described in Methods. Figure The bimodal distribution adopted relied on the existence of significant differences between morning and evening maxima and the minima observed before sunrise and at early afternoon. For the intervals 02:00 – 07:00 h and 08:00 – 12:00 h, each hourly MI incidence differed by more than 1 SD from daily mean (4 ± 2) %/h. In the case of the 13:00 – 24:00 h interval, mean hourly MI incidence was 4.4 ± 0.9 %/h, with values at 15:00, 16:00 and 19:00 h differing by >1 SD from the mean. This supported the existence of a minimum at 13:00 – 15:00 h and a maximum at 16:00 – 20:00 h, significantly above random noisey(t), to illustrate the contribution of each parameter in fitting the function. Overall, the fitted function accounted for 84.6 % of variance. Amplitude values for the cosinor component were A = (2.6 ± 0.3) %/h and B = (2.3 ± 0.4) %/h with an acrophase (tacrophase) of 18.8 ± 0.6 h . Integration over 24 h yielded a probability of 63 ± 7 % for the cosinor component  at 9.9 ± 0.2 h  with a standard deviation (σ) of 2.0 ± 0.3 h. The probability of the gaussian component was 37 ± 7 %.Figure ent Fig. . The gauWhen the analysis depicted in Fig. The acrophase of the cosinor component occurred between 17:25 and 19:10 h in the total population and in the excluding subgroups while gaussian maximum was at 10:00 h with a SD of ± 2 h. Differences in these parameters between each pair of excluding subpopulations or against total population were non-significant.Almost all cardiovascular events exhibit a pronounced circadian rhythm, with higher frequencies in the morning when patients wake up, resume upright posture and begin activities, and a relatively lower risk during sleep. These circadian rhythms, although anchored genetically, are synchronized and maintain certain phase relationships to external factors, especially the sleep portion of the light-dark schedule ,29. SuchThe foregoing results describing a cohort of 1063 patients recruited from 65 CCU located in Argentina and Uruguay who were admitted to the CCU within 24 h of the onset of symptoms of an acute MI, point out to the existence of two maxima in the incidence of MI, at the morning  and at the afternoon . A nadir in nocturnal MI incidence (1.3 %/h between 03:00 and 07:00 h) and a secondary minimum at early afternoon (3.8 %/h between 13:00 and 15:00 h) also occurred. The best fit curve (explaining ca. 85% of variance) was a 24 h cosinor  with a symmetrical gaussian "bell" .A similar bimodal picture was observed for MI frequencies among different excluding subgroups . Proportion between cosinor and gaussian probabilities was maintained among most subgroups except for older patients who tended to have more MI at the afternoon and for patients with previous symptoms, who had MI equally distributed between the morning and the afternoon maxima.Following the proposed model, the population of patients in the present examined sample could be divided into those having more risk of MI in the morning (described by the gaussian function), and in those having more risk during the evening (described by the 24 h cosinor function). For subjects in the "cosinor distribution", the amplitude of oscillation B resulted similar to the value of constant A (B/A ratio near unity), indicating a strong oscillation in MI episodes over the daily mean value of cosinor. Minimal (but not zero) MI incidence occurs at 07:00 h, which slowly rises up to maximum at 19:00 h and then slowly declines toward the minimum at 07:00 h.For patients in the "gaussian distribution" a high incidence in MI was seen during the morning (maximum ~ 10:00 h). For these patients MI begins to occur at 04:00 h and attains its maximum at 10:00 h with a fast decline towards 16:00 h. In this group MI episodes resulted virtually absent between 16:00 and 04:00 h. At the evening, the observed MI's belong only to the "cosinor group" while during morning hours, most of recorded MI's were suffered by the "gaussian group" plus a minor fraction (slowly increasing as time elapsed) of the "cosinor group".Time dependence and width of peaks (described by phase lag of the cosinor or time of mean and SD of gaussian adjust) remained the same in the different excluding subgroups extracted from total population. Likewise, the fraction of population associated to each component (approximately 40% gaussian/60% cosinor) was independent on the subgroup under consideration, except for patients older than 70 years and patients with previous symptoms. Indeed, older individuals appeared to double the chance to suffer a MI during the evening in comparison to morning hours (83% of the older patients suffered MI at evening vs. 17% in the morning). It should be noted that older and anterior infarct populations showed a significant increase in threshold above which the cosinor fitting is mounted. While the minimum for the different cosinors showed a mean value of 0.46 ± 0.44 %/h (SD) the two populations mentioned showed mean values that differed for more than 2 SD over the mean in a one-tailed normal test. This could be interpreted as the occurrence of extra risk factor (s) whose probability maintains constant during the day.The high susceptibility of this Argentine and Uruguayan population to show MI at the evening points out to the relevance of variations in the spectrum of cardiovascular disease between different regions of the world and ethnic groups -25. IndeThe prevalence of afternoon episodes in the present sample as compared to other studies could be related to a different daytime schedule, exposure to light, meals or disparities in cardiovascular risk factors, e.g. smoking. A prolonged siesta, which is a common practice in the present Argentine and Uruguayan population, could be followed by an increase in heart rate and blood pressure as it happens after waking up in the morning , leadingChanges in heart rate, blood pressure, neural and humoral vasoactive factors and heart contractility are presumably involved in the increase of myocardial oxygen demand that predisposes to the ischemic attack -39. In aWe are aware of the limitations of the present study. Determination of time of MI based on symptom onset could be subject to a bias, because it is possible that some people could have had symptoms for some hours and have called an ambulance later . Taking The author(s) declare that they have no competing interests.All authors have made substantial contributions to design of the analysis and the interpretation of data; and have been involved in drafting the article and revising it critically for important intellectual content; and have given final approval of the version to be published.The pre-publication history for this paper can be accessed here:Curve fitting for MI probability density to MI incidence. Curve fitting for MI probability density to MI incidence for the total population of patients as for the excluding subgroups.Click here for file


Despite advances in survival in patients with thalassemia major (TM) the most common cause of death is cardiac disease. Regular cardiac follow-up is imperative in order to identify and reverse pathology. Cardiac Magnetic Resonance (CMR) and Echocardiography (US) are applied in parallel to TM patients for cardiac evaluation and ongoing monitoring. A comparison between mutual features would be useful in order to assess the accuracy and reliability of the two methods, with a particular focus on routine US application. TM's special attributes offer an excellent opportunity for cardiac imaging research that has universal general purpose applications.135 TM patients underwent US (Teichholz's M-mode formula – rapidly accessible means of measuring volumes and ejection fraction) and CMR volumetry. Paired-samples t-test, Passing & Badlock regression and Bland & Altman plot were used while comparing the common parameters between the CMR and the US.We found that the US volumes were underestimated, especially the end-diastolic volume (p < 0.001). The end-systolic volume showed a borderline two-tailed probability (p ≈ 0.05). The correlation for the ejection fraction was acceptable (r = 0.60) without a statistically significant difference (p = 0.37) and the Bland Altman plot range was narrow (25.8%). There was a satisfactory correlation of the US' shortening fraction with CMR's ejection fraction (r = 0.58).In cases where cardiac wall movement abnormalities are absent, the US Teichholz's M-mode formula for volume measurements, though less sophisticated in comparison to the high resolution CMR technique, offers an adequate ejection fraction estimation for routine use, especially when monitoring gross alterations in cardiac function over time, and is easy to perform. Patients with homozygous, transfusion dependent thalassemia (TM) exhibit a broad spectrum of cardiac pathology due to the nature of their disease. Methods of cardiac imaging, such as the US and CMR, assess cardiac function in thalassemia major and estimate the extent of damage. Having in mind the special attributes of this patient population and their need for frequent evaluation of heart performance and cardiac iron load with US and CMR , TM offeEchocardiography (US) is a very useful examination since its application is widespread, safe, economical and very commonly used in every day medical practice. However the image acquisition depends on the operator and the acoustic window . ReproduThe most recent advance in cardiac imaging is with Cardiac Magnetic Resonance (CMR). Like echocardiography, it is free of ionizing radiation, non-invasive and reliable. In addition it's independent of geometric assumptions ,7 and haConsidering the above, a comparison between mutual features would be useful in order to assess the accuracy and reliability of the two methods, with a particular focus on routine US application. From the common measured left ventricle (LV) parameters in both techniques the end-diastolic volume (EDv), the end-systolic volume (ESv), the stroke volume (Sv) and, most importantly, the ejection fraction (EF) are very important in assessing the overall heart performance and help classify patients in condition related risk groups.2 and the mean heart rate was 78.81 (± 10.34) beats per minute. Patients in whom cardiac medication was introduced between studies were excluded from the comparison analysis, due to the possible influence with either study's results.One hundred and thirty five (135) patients with TM attending an outpatient clinic, regularly transfused at approximately two weekly intervals and with regular chelation therapy, were assessed with CMR and had ultrasound cardiac assessment within an interval of 1 month from their CMR (prior or later). There were 72 females and 63 males with a mean age of 29.96 (± 5.91) years. The mean body surface area was 1.66 (± 0.17) mComplete M-mode, two-dimensional and Doppler  echocardiography was performed at rest, using an Aloca ProSound SSD 5500 ultrasound system . Patients were examined in the mid-interval between two scheduled transfusions. The same applied for the CMR study. All echocardiographic and Doppler studies were carried out by the same observer (AA). Chamber dimensions were measured according to the recommendations of the American Society of Echocardiography (ASE)  using M-3, with LVId being the LV internal dimension (end-diastole and end-systole respectively).V = [7/(2.4 + LVId)]·[LVId]A cardiac-dedicated 1.5 Tesla MR imager  with 40 mT/m gradients, phase array-cardiac rf coil and appropriate cardiac software was used for the CMR measurements. Cardiac volumes and ejection fractions were calculated offline in GE's "Advantage Windows" Workstation using GE's proprietary software MASS_PLUS. GE's algorithm for calculating cardiac volumes is based on a 3D method . Additional imaging parameters included a single excitation, a matrix of 224 × 224, bandwidth of 125 kHz, slice thickness of 8 mm, and electrocardiogram (ECG) gating. Each slice in 2-chamber, 4-chamber and short-axis view was acquired in a single breath-hold (15–20 sec), with a 20 phases per cardiac cycle. Cardiac volumes, and thereby ejection fraction and stroke volume, were assessed from 10–12 short-axis slices from the base to the apex of the heart. Although automation worked quite well, manual corrections had to be made occasionally in order to ensure the accuracy of the measurements. All measurements were performed by the same operator (EG). The unit was validated through the Brompton site with five patients who had CMR, once in Athens, then London then again in Athens all within a three week period and showed that the reproducibility was within a 5% confidence [1 + A2 + A3 + ... + An) × 8 mm, with A1 to An being the area of each of the 10–12 short-axis slicesV =  using paired-samples t-test, Passing & Badlock regression and Bland & Altman plot when comparing the common features between the CMR and the US. The p values were regarded as significant when <0.05. Continuous variables are expressed as mean ± 1 SD. For correlation, r > 0.5 was considered significant.The Institutional Review Board approved the study and all subjects signed written consent for the anonymous publication of their data.Table Table Figures For this study we used information from a large number of patients  who had undergone a CMR examination for follow-up on their cardiac iron overload (T2* score) in parallel to their routine echocardiogram. The US technique employed by our research team did not implement latest technological advances and measurements were calculated with a relatively simple algorithm in order to evaluate one of the most common and rapidly accessible means of measuring EF via US against the high resolution CMR technique.Our study demonstrated a mild discrepancy of values in the net volume (diastolic and systolic) comparison, with the US derived measurements being relatively and systematically underestimated. However this consistent underestimation was proportionally equal within the diastolic and systolic volume calculations leading to extremely similar ejection fractions between the two methods.In two studies by Bellenger et al ,27 whereAn earlier study by the same research team  in a carIn the present study, due to patients' intolerance to multiple evaluations and significant examination cost, particularly CMR's, we were unable to perform an interstudy reproducibility analysis of both methods. We do believe however that this represents a small limitation to this work.The good correlation and the lack of statistically significant difference between the measurements of the two techniques for ejection fraction indicate that both methods are accurate and interchangeable for that assessment. In cases where application requirements described are met, the US Teichholz's M-mode formula for volume measurements, though less sophisticated in comparison to the high resolution CMR technique, offers an adequate EF estimation for routine use, especially when monitoring gross alterations in cardiac function over time, and is easy to perform, in contrast to the not always readily available CMR technique.With respect to conflicts of interest, Professor Aessopos has received travel assistance for conferences from Novartis Hellas and Demos and Dr. Berdoukas is a consultant for ApoPharma Inc. (Canada) and holds a confidentiality agreement with Novartis for the development of the drug Exjade.Dr. Giakoumis and Dr. Gotsis declare that they have no competing interests.AG conceived and designed the study, carried out the acquisition and statistical analysis of data and drafted the manuscript.VB assisted in the statistical analysis of data, interpretation of results and manuscript drafting.EG carried out the CMR volumetry study.AA carried out the US volumetry study, interpreted results, revised the manuscript for important intellectual content and coordinated the whole process.All authors read and approved the final manuscript.