Treatment of ventricular tachycardia by transcatheter radiofrequency ablation in patients with ischemic heart disease. Elimination of Local Abnormal Ventricular Activities: A New End Point for Substrate Modification in Patients With Scar-Related Ventricular Tachycardia Catheter Ablation for the Treatment of Electrical Storm in Patients With Implantable Cardioverter-Defibrillators: Short- and Long-Term Outcomes in a Prospective Single-Center Study Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial Randomized controlled study of detection enhancements versus rate-only detection to prevent inappropriate therapy in a dual-chamber implantable cardioverter-defibrillator. Japanese randomized trial for investigation of a combined therapy of amiodarone and implantable cardioverter defibrillator in patients with ventricular tachycardia and fibrillation: the Nippon ICD Plus Pharmachologic Option Necessity study design. Incidence and predictors of major complications from contemporary catheter ablation to treat cardiac arrhythmias. The 1+1 Trial: A Prospective Trial of a Dual- Versus a Single-Chamber Implantable Defibrillator in Patients With Slow Ventricular Tachycardias Long-term incidence of malignant ventricular arrhythmia and shock therapy in patients with primary defibrillator implantation does not differ from event rates in patients treated for survived cardiac arrest. Cost-effectiveness of catheter ablation in patients with ventricular tachycardia. Factors influencing appropriate firing of the implanted defibrillator for ventricular tachycardia/fibrillation: findings from the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II). Comparative long-term outcomes after cardiac resynchronization therapy in right ventricular paced patients versus native wide left bundle branch block patients. Catheter ablation in selected patients with depressed left ventricular ejection fraction and persistent atrial fibrillation unresponsive to current cardioversion. A strategy to achieve CRT response in permanent atrial fibrillation without obligatory atrioventricular node ablation. Analysis of implantable cardioverter defibrillator therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial. Appropriate and Inappropriate Ventricular Therapies, Quality of Life, and Mortality Among Primary and Secondary Prevention Implantable Cardioverter Defibrillator Patients: Results From the Pacing Fast VT REduces Shock ThErapies (PainFREE Rx II) Trial Effect of increased current, multiple pacing sites and number of extrastimuli on induction of ventricular tachycardia.
BACKGROUND Recurrent sustained ventricular tachycardia ( VT ) is not responsive to antiarrhythmic drugs in the majority of patients , who therefore need therapy with nonpharmacological methods . We evaluated prospect ively the feasibility , safety , and efficacy of transcatheter radiofrequency ( RF ) ablation of VT in 21 selected patients with ischemic heart disease and VT . METHODS AND RESULTS Twenty-one patients with ischemic heart disease and recurrent , drug-refractory VT documented by 12-lead ECG were selected who had sufficient hemodynamic tolerance of VT to undergo transcatheter mapping . Documented clinical VT was reproduced by programmed cardiac stimulation ( PCS ) , and the site of origin was localized by a combination of techniques , including pace mapping , activation-sequence mapping , recordings of middiastolic potentials , and application of re setting and entrainment principles . RF current at 55 V was applied ( 3.8 + /- 3.1 applications per patient ) for as long as 30 seconds at a time to target sites . Twenty-four distinct clinical VTs ( mean cycle length , 445 + /- 52 milliseconds ) were mapped and ablated in 21 patients . In 17 of 21 patients ( 81 % ) , the procedure was acutely successful , and the target clinical VT could no longer be induced by PCS after the procedure , whereas in 4 patients , clinical VT remained inducible . By contrast , VTs with shorter cycle length and different QRS morphology than the ablated VT could still be induced by PCS in 12 of 21 patients . One patient died in intractable congestive heart failure 10 days after the procedure , and the remaining 20 are alive at the end of the follow-up period . The majority of the patients continued to be treated with at least one additional mode of antiarrhythmic therapy ; 12 patients were still taking antiarrhythmic drugs , and 9 patients received an implantable cardioverter/defibrillator . During a mean follow-up period of 13.2 + /- 5.0 months , 9 of 20 patients ( 45 % ) had recurrent VT . In 4 patients , the recurrent VT was different than the previously ablated one . Clinical VT recurred in all 4 patients in whom RF ablation had been acutely unsuccessful . Four patients with recurrent VT underwent repeat RF ablation procedures that were acutely successful and had no further recurrence . CONCLUSION Transcatheter RF ablation is feasible but has only moderately high efficacy in a small , selected group of patients with ischemic heart disease and drug-refractory , highly frequent , hemodynamically tolerated , sustained VT . In the majority of the patients , this treatment technique is palliative rather than definitive , and many of the patients continue to require other methods of antiarrhythmic therapy Background — Catheter ablation of ventricular tachycardia ( VT )  is effective and particularly useful in patients with frequent defibrillator interventions . Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT . Noninducibility is the most frequently used end point but is associated with significant limitations , so the optimal end point remains unclear . We hypothesized that elimination of local abnormal ventricular activities ( LAVAs ) during sinus rhythm or ventricular pacing would be a useful and effective end point for substrate-based VT ablation . As an adjunct to this strategy , we used a new high-density mapping catheter and frequently used epicardial mapping . Methods and Results — Seventy patients ( age , 67±11 years ; 7 female ) with VT and structurally abnormal ventricle(s ) were prospect ively enrolled .  Conventional mapping was performed in sinus rhythm in all , and a high-density Pentaray mapping catheter was used in the endocardium ( n=35 ) and epicardially . LAVAs were recorded in 67 patients ( 95.7 % ; 95 % confidence interval , 89.2–98.9 ) . Catheter ablation was performed targeting LAVA with an irrigated-tip catheter placed endocardially via a transseptal or retro grade aortic approach or epicardially via the subxiphoid approach . LAVAs were successfully abolished or dissociated in 47 of 67 patients ( 70.1 % ; 95 % confidence interval , 58.7–80.1 ) . In multivariate analysis , LAVA elimination was independently associated with a reduction in recurrent VT or death ( hazard ratio , 0.49 ; 95 % confidence interval , 0.26–0.95 ; P=0.035 ) during long-term follow-up ( median , 22 months ) . Conclusions — LAVAs can be identified in most patients with scar-related VT . Elimination of LAVAs is feasible and safe and is associated with superior survival free from recurrent VT Background — Electrical storm ( ES ) caused by recurrent episodes of ventricular tachycardia ( VT ) can cause sudden death in patients with implantable cardioverter-defibrillators and adversely affects prognosis in survivors . Catheter ablation has been proposed for treating ES , but its long-term effect in a large population has never been verified . Methods and Results — Ninety-five consecutive patients with coronary artery disease ( 72 patients ) , idiopathic dilated cardiomyopathy ( 10 patients ) , and arrhythmogenic right ventricular dysplasia/cardiomyopathy ( 13 patients ) undergoing catheter ablation for drug-refractory ES  were prospect ively evaluated . Short-term efficacy was defined by a complete protocol of programmed electric stimulation and by in-hospital outcome ; long-term analysis addressed ES recurrence , cardiac mortality , and VT recurrence . Pleomorphic/nontolerated VTs required electroanatomic and noncontact mapping in 48 and 22 patients , respectively , and percutaneous cardiopulmonary support in 10 patients . An epicardial approach was used in 10 patients . After 1 to 3 procedures , induction of any clinical VT(s ) by programmed electrical stimulation was prevented in 85 patients ( 89 % ) . ES was acutely suppressed in all patients ; a minimum period of 7 days with stable rhythm was required before hospital discharge . At a median follow-up of 22 months ( range , 1 to 43 months ) , 87 patients ( 92 % ) were free of ES and 63 patients ( 66 % ) were free of VT recurrence . Eight of 10 patients with persistent inducibility of clinical VT(s ) had ES recurrence ; 4 of them died suddenly despite appropriate implantable cardioverter-defibrillator intervention . All together , 11 of 95 patients ( 12 % ) died of cardiac-related reasons . In the group of patients presenting with all clinical VTs acutely abolished , no ES recurrence was documented , and cardiac mortality was significantly lower compared with the group of patients showing ≥1 clinical VT still inducible after catheter ablation . Conclusions — Advanced strategies of catheter ablation applied to a large population of patients are effective in the short-term treatment of ES . By preventing ES recurrence , catheter ablation may play a protective role over the long term and , together with long-term pharmacological therapy , may favorably affect cardiac mortality BACKGROUND In patients with ventricular tachycardia ( VT ) and a history of myocardial infa rct ion , intervention with an implantable cardioverter defibrillator ( ICD ) can prevent sudden cardiac death and thereby reduce total mortality . However , ICD shocks are painful and do not provide complete protection against sudden cardiac death . We assessed the potential benefit of catheter ablation before implantation of a cardioverter defibrillator . METHODS The Ventricular Tachycardia Ablation in Coronary Heart Disease ( VTACH ) study was a prospect i ve , open , r and omised controlled trial , undertaken in 16 centres in four European countries . Patients aged 18 - 80 years were eligible for enrolment if they had stable VT , previous myocardial infa rct ion , and reduced left-ventricular ejection fraction ( LVEF ; < or=50 % ) . 110 patients were r and omly allocated in a 1:1 ratio to receive catheter ablation and an ICD ( ablation group , n=54 ) or ICD alone ( control group , n=56 ) . R and omisation was done by computer-generated r and omly permuted blocks and stratified by centre and LVEF ( < or=30 % or > 30 % ) . Patients were followed up for at least 1 year . The primary endpoint was the time to first recurrence of VT or ventricular fibrillation ( VF ) . Analysis was by intention to treat ( ITT ) . This study is registered with Clinical Trials.gov , number NCT00919373 . FINDINGS 107 patients were included in the ITT population ( ablation group , n=52 ; control group , n=55 ) . Two patients ( one in each group ) withdrew consent immediately after r and omisation without any follow-up data and one patient ( ablation group ) was excluded because of a protocol violaton . Mean follow-up was 22.5 months ( SD 9.0 ) . Time to recurrence of VT or VF was longer in the ablation group ( median 18.6 months [ lower quartile 2.4 , upper quartile not determinable ] ) than in the control group ( 5.9 months [ IQR 0.8 - 26.7 ] ) . At 2 years , estimates for survival free from VT or VF were 47 % in the ablation group and 29 % in the control group ( hazard ratio 0.61 ; 95 % CI 0.37 - 0.99 ; p=0.045 ) . Complications related to the ablation procedure occurred in two patients ; no deaths occurred within 30 days after ablation . 15 device-related complications requiring surgical intervention occurred in 13 patients ( ablation group , four ; control group , nine ) . Nine patients died during the study ( ablation group , five ; control group , four ) . INTERPRETATION Prophylactic VT ablation before defibrillator implantation seemed to prolong time to recurrence of VT in patients with stable VT , previous myocardial infa rct ion , and reduced LVEF .  Prophylactic catheter ablation should therefore be considered before implantation of a cardioverter defibrillator in such patients . FUNDING St Jude Medical OBJECTIVES The purpose of this study was to compare rate-only detection to enhanced detection in a dual-chamber implantable cardioverter-defibrillator ( ICD ) , to discriminate ventricular tachycardia from supraventricular tachycardia . BACKGROUND ICDs are highly effective in treating ventricular tachycardia ( VT ) or ventricular fibrillation ( VF ) . However , they frequently deliver inappropriate therapy during supraventricular tachycardia ( SVT ) . METHODS We conducted a r and omized clinical trial of detection enhancements in a dual-chamber ICD compared to control ( rate-only ) detection to discriminate VT from SVT . Detection enhancements included a specific st and ardized protocol identical for all patients for programming rate stability , sudden onset , atrial-to-ventricular relationship ( sudden onset = 9 % and rate stability = 10 ms ; V > A " on " ) , and " sustained rate duration " ( 3 minutes ) . The primary endpoint was the time to first inappropriate therapy classified by a blinded events committee . RESULTS One hundred forty-nine patients had a history of sustained VT or VF . Mean age ( + /- SD ) was 60 + /- 13 years ; 83 % were male , and mean ejection fraction was 35 + /- 15 % . Control ( n = 70 ) and " enhanced " ( n = 79 ) groups did not differ with regard to age , sex , ejection fraction , or primary arrhythmia . The proportion of patients free of inappropriate therapy over time was significantly higher in the enhanced versus the control group ( hazard ratio = 0.47 , P = .011 ) . High-energy shocks were reduced from 0.58 + /- 4.23 shocks/patient/month in the control group to 0.04 + /- 0.15 shocks/patient/month in the enhanced group ( P = .0425 ) . No patient programmed per protocol failed to receive therapy for VT detected by the ICD ( 422 VT episodes ) . CONCLUSIONS St and ardized programming in a dual-chamber ICD leads to a significant and clinical ly important reduction in inappropriate therapies compared to rate-only detection and does not compromise safety with respect to appropriate treatment of VT BACKGROUND Implantable cardioverter-defibrillators ( ICDs ) are the most effective therapy in reducing the mortality of patients with life-threatening ventricular tachyarrhythmias . However , the ICD can not prevent the recurrence of tachycarida attacks and that limits the clinical usefulness of them . The Nippon ICD Plus Pharmachologic Option Necessity ( NIPPON ) trial was design ed as the first prospect i ve r and omized study to test the hypothesis whether amiodarone could improve the patient 's clinical outcome by reducing the amount of ICD therapy in the Japanese patient population . METHODS AND RESULTS Approximately 400 patients with organic heart disease and spontaneous episode(s ) of sustained ventricular tachycardia/fibrillation ( VT/VF ) will be r and omly assigned to one of 2 groups ; the amiodarone group and non-amiodarone group . Both groups of patients will be followed at least for 24 months . The end-point committee will adjudicate events in a blinded fashion . The primary end-points of this study are determination of the appropriate therapy from the ICD and alteration of the assigned treatment because of its harmful effects and /or frequent ICD therapies . CONCLUSION The NIPPON study is expected to confirm our underst and ing of the prognostic and therapeutic usefulness of adjuvant amiodarone therapy for patients with an ICD and with a history of sustained VT/VF BACKGROUND Up date d underst and ing of the risks of catheter ablation is important because techniques have evolved for procedures treating non-life-threatening as well as potentially lethal arrhythmias . OBJECTIVE This prospect i ve study sought to assess the incidence and predictors of major complications from contemporary catheter ablation procedures at a high-volume center . METHODS Over a 2-year period , 1,676 consecutive ablation procedures  were prospect ively evaluated for major complications throughout 30 days postprocedure . Predictors of major complications were determined in a multivariate analysis adjusted for demographics , clinical variables , ablation type , and procedural factors . RESULTS Rates of major complications differed between procedure types , ranging from 0.8 % for supraventricular tachycardia , 3.4 % for idiopathic ventricular tachycardia ( VT ) , 5.2 % for atrial fibrillation ( AF ) , and 6.0 % for VT associated with structural heart disease ( SHD ) .  Ablation type ( ablation for AF [ odds ratio ( OR ) 5.53 , 95 % confidence interval ( CI ) 1.81 to 16.83 ] , for VT with SHD [ OR 8.61 , 95 % CI 2.37 to 31.31 ] , or for idiopathic VT [ OR 5.93 , 95 % CI 1.40 to 25.05 ] all referenced to supraventricular tachycardia ablation ) , and serum creatinine level > 1.5 mg/dl ( OR 2.48 , 95 % CI 1.07 to 5.76 ) were associated with increased adjusted risk of major complications , whereas age , gender , body mass index , international normalized ratio level , hypertension , coronary artery disease , diabetes , and prior cerebrovascular accident were not associated with increased risk . CONCLUSION In a large cohort of contemporary catheter ablation  , major complication rates ranged between 0.8 % and 6.0 % depending on the ablation procedure performed . Aside from ablation type , renal insufficiency was the only independent predictor of a major complication Background —The tachycardia detection interval ( TDI ) in  implantable cardioverter/defibrillators ( ICDs ) is conventionally programmed according to the slowest documented ventricular tachycardia ( VT ) , with a safety margin of 30 to 60 ms . With this margin , VTs above the TDI may occur . However , longer TDIs are associated with an increased risk of inappropriate therapy . We hypothesized that patients with slow VTs ( < 200 bpm ) may benefit from a long TDI and a dual-chamber detection algorithm compared with a conventionally programmed single-chamber ICD . Methods and Results — Patients with VTs < 200 bpm were implanted with a dual-chamber ICD  that was r and omly programmed to a dual-chamber algorithm and a TDI of ≥469 ms or to a single-chamber algorithm with a TDI 30 to 60 ms above the slowest documented VT cycle length and the enhancement criteria of cycle length variation and acceleration . The primary combined end point was the number of all inappropriate therapies , VTs above the TDI , and VTs with significant therapy delay ( > 2 minutes ) . After 6 months , a crossover analysis was performed . Total follow-up was 1 year . One hundred two patients were included in the study . The programmed TDI was 500±36 ms during the dual-chamber phase and 424±63 ms during the single-chamber phase . For the primary end point ( inappropriate therapies , VTs above the TDI , or VTs with detection delay ) , a moderate superiority of the dual-chamber mode was found : Mann-Whitney estimator=0.6661 ; 95 % CI , 0.5565 to 0.7758 ; P=0.0040 . Conclusions —Dual-chamber detection with a longer TDI improves VT detection and does not increase the rate of inappropriate therapies despite a considerable increase in tachycardia burden INTRODUCTION Recent trials have demonstrated benefit of prophylactic defibrillator ( ICD ) implantation compared to conventional treatment in high-risk patients . However , many patients have rare or no sustained arrhythmias following implantation . Our study addresses the question , whether patients with prophylactic defibrillator implantation  have a lower risk for life-threatening ventricular tachycardia ( VT ) or ventricular fibrillation ( VF ) compared to sudden cardiac death ( SCD ) survivors . METHODS AND RESULTS Over 7 years we enrolled 245 patients . Occurrence of spontaneous sustained VT/VF result ing in adequate ICD treatment was the endpoint . Incidence , type , and treatment of sustained arrhythmia in 43 previously asymptomatic ICD recipients ( group B ) were compared to data of 202 survivors of imminent SCD ( group A ) . All patients had severely impaired left ventricular ejection fraction ( < 45 % ) . Group B patients had long runs ( > 6 cycles , < 30 s ) of VT during Holter monitoring and inducible sustained arrhythmia . Incidence of rapid VT and VF ( cycle length < 240 ms/heart rate > 250 bpm ) after 4 years ( 35 % in both groups , P = ns ) and adequate defibrillator therapies ( 57 % vs 55 % , P = ns ) were similar in both groups after univariate and multivariate analysis . Cumulative mortality tended to be lower in group B compared to group A , but the difference was not statistically significant . CONCLUSION During long-term follow-up , incidence of sustained rapid ventricular arrhythmia in prophylactically treated patients is as high as that of SCD survivors . Benefit from defibrillator implantation for primary prevention ( group B ) appears to be comparable to that for survived cardiac arrest ( group A ) BACKGROUND This study evaluated the cost-effectiveness of catheter ablation therapy versus amiodarone for treating ventricular tachycardia ( VT ) in patients with structural heart disease . The analysis used a societal perspective for a hypothetical cohort of VT patients with implantable cardioverter-defibrillators , who were experiencing frequent shocks . METHODS AND RESULTS We calculated incremental cost-effectiveness of ablation relative to amiodarone over 5 years after treatment initiation . Event probabilities were from the Chilli r and omized clinical trial ( Chilli Cooled Ablation System , Cardiac Pathways Corporation , Sunnyvale , Calif ) , the literature , and a consensus panel . Costs were from 1998 national Medicare reimbursement schedules . Quality -of-life weights ( utilities ) were estimated using an established preference measurement technique . In a hypothetical cohort of 10 000 patients , 5-year costs were higher for patients undergoing ablation compared with amiodarone therapy ( $ 21 795 versus $ 19 075 ) . Ablation also produced a greater increase in quality of life ( 2.78 versus 2.65 quality -adjusted life-years [ QALYs ] ) . This yielded a cost-effectiveness ratio of $ 20 923 per QALY gained for ablation compared with amiodarone . Results were relatively insensitive to assumptions about ablation success and durability . In less severe patients with good ejection fractions who suffer their first VT episode , the incremental cost-effectiveness ratio was $ 6028 per QALY gained . These cost-effectiveness ratios are within the range generally thought to warrant technology adoption . CONCLUSIONS This study demonstrates that , from a societal perspective , catheter ablation appears to be a cost-effective alternative to amiodarone for treating VT patients OBJECTIVES The purpose of this study was to prospect ively examine the role of clinical , laboratory , echocardiographic , and electrophysiological variables as predictors of appropriate initial implantable cardioverter-defibrillator ( ICD ) therapy for ventricular tachycardia ( VT ) or ventricular fibrillation ( VF ) or death in the Multicenter Automatic Defibrillator Implantation Trial II ( MADIT-II ) population . BACKGROUND There is limited information regarding the determinants of appropriate ICD therapy in patients with reduced ventricular function after a myocardial infa rct ion . METHODS We used secondary analysis in one arm of a multicenter r and omized clinical trial in patients with a previous myocardial infa rct ion and reduced left ventricular function . RESULTS We analyzed baseline and follow-up data on 719 patients enrolled in the ICD arm of the MADIT-II study . Appropriate ICD therapy was observed in 169 subjects . Clinical , laboratory , echocardiographic , and electrophysiological variables , along with measures of clinical instability such as interim hospitalization for congestive heart failure ( IH-CHF ) and interim hospitalization for coronary events ( IH-CE ) , were examined with proportional hazards models and Kaplan-Meier time-to-event curves before and after first interim hospitalization . Interim hospitalization-CHF , IH-CE , no beta-blockers , digitalis use , blood urea nitrogen ( BUN ) > 25 , body mass index ( BMI ) > or = 30 kg/m2 , and New York Heart Association functional class > II were associated with increased risk for appropriate ICD therapy for VT , VF , or death . In a multivariate ( stepwise selection ) analysis , IH-CHF was associated with an increased risk for the end point of either VT or VF ( hazard ratio [ HR ] 2.52 , 95 % confidence interval [ CI ] 1.69 to 3.74 , p < 0.001 ) and for the combined end point of VT , VF , or death ( HR 2.97 , 95 % CI 2.15 to 4.09 , p < 0.001 ) . Interim hospitalization-CE was associated with an increased risk for VT , VF , or death ( HR 1.66 , 95 % CI 1.09 to 2.52 , p = 0.02 ) . CONCLUSIONS These results provide important mechanistic information , suggesting that worsening clinical condition and cardiac instability , as reflected by an IH-CHF or IH-CE , are subsequently associated with a significant increase in the risk for appropriate ICD therapy ( for VT/VF ) and death BACKGROUND The current guidelines do not clearly state when we should up grade a patient with right ventricular pacing ( RVP ) to cardiac resynchronization therapy ( CRT )  , although the deleterious effect of chronic RVP has been established with recent trials . OBJECTIVES The aims of this study were to compare the long-term survival after CRT in patients up grade d from RVP with that in patients with left bundle branch block ( LBBB ) with QRS duration ≥ 150 ms and to compare the mechanical properties associated with CRT response in these groups . METHODS Overall , 135 patients with implanted CRT from a single center ( 85 ( 63 % ) with native wide LBBB and 50 ( 37 % ) with RVP ) were studied prospect ively . Baseline left ventricular typical contraction pattern was determined using speckle tracking echocardiography in the apical 4-chamber view . The predefined end point was death , heart transplantation , or left ventricular assist device implantation over a period of 4 years . RESULTS Patients with RVP had a significantly favorable long-term outcomes with adjusted hazard ratio of 0.36 ( 95 % confidence interval 0.14 - 0.96 ; P = .04 ) . Both groups had ~70 % of patients with typical contraction pattern . The absence of typical contraction pattern was associated with a higher risk of an end point with adjusted hazard ratio of 5.43 ( 95 % confidence interval 2.31 - 12.72 ; P < .001 ) . In patients with typical contraction pattern , activation of the apical septal segment occurred more frequently in the RVP group and of the base or mid septal segments in the LBBB group . CONCLUSION Patients with HF up grade d from RVP have more favorable long-term outcomes  after CRT than do native LBBB patients with QRS duration ≥ 150 ms . Contraction pattern assessment can be used to identify potential responders in the RVP group AIMS In congestive heart failure ( CHF ) patients with persistent atrial fibrillation ( AF ) , direct current cardioversion ( DCC ) may reveal participation of tachycardiamediated process to left ventricular ( LV ) dysfunction by restoring sinus rhythm ( SR ) . However , if DCC fails to restore SR , patients ' management remains challenging . The aim of the study was to assess the AF catheter ablation benefit in a selected group of CHF patients with LV ejection fraction ( LVEF ) < 40 % and persistent AF unresponsive to DCC , in whom a tachycardia-mediated process is thought to be predominant . METHODS AND RESULTS Between January 2008 and September 2011 , among 129 CHF patients with persistent AF referred to our institution , 34 ( 63.8 ± 9-year old , 24 men ) presented AF refractory to DCC with an estimated high likelihood of tachycardia-mediated LV dysfunction according to a specific set of criteria . These 34 patients underwent stepwise AF ablation and were closely followed up . After a mean 1.9 AF ablation procedures per patient and 17.6 ± 7 months after the last procedure , all patients were in SR . The New York Heart Association class improved from 2.8 ± 0.3 to 1 ± 0.2 ( P < 0.001 ) and the LVEF increased from 30.4 ± 6 to 54.6 ± 6 % ( P < 0.0001 ) after 3 - 6 months of SR , with a persistent benefit as long as the SR was maintained . CONCLUSION Atrial fibrillation catheter ablation in selected CHF patients with persistent AF refractory to DCC and without any other evidence for secondary LV dysfunction leads to a substantial LVEF improvement in the majority of them . However , redo procedures are frequent in order to achieve mid-term SR maintenance BACKGROUND Cardiac resynchronization therapy ( CRT ) is an established method in patients with severe heart failure and wide QRS configuration , particularly during sinus rhythm ( SR ) . In CRT patients with permanent atrial fibrillation ( AF ) , there is no general consensus regarding the need for atrioventricular node ( AVN ) ablation . The aim of this study was to evaluate the benefit of CRT in permanent AF with and without AVN ablation . METHODS New York Heart Association classification , QRS duration , and echocardiographic parameters were assessed before and after CRT with a follow-up of 12 ± 3 months . Two hundred thirty patients in SR and 46 patients with permanent AF of 2.1 ± 0.5 years duration were studied .  AVN ablation was performed only in AF patients with insufficient pharmacological rate control evidence d by ≤80 % ventricular stimulation . RESULTS Fifteen AF patients underwent AVN ablation . Biventricular pacing comparably improved functional status , left ventricular ejection fraction , and left ventricular end-diastolic dimensions in all treated groups . Biventricular stimulation percentage was 10 % lower in pharmacologically treated AF patients over 1 year as compared to patients in SR and to AF patients undergoing AVN ablation , which did not affect outcome in this patient population . CONCLUSION In patients with permanent AF and CRT , an AVN ablation strategy might not be strictly required in all patients INTRODUCTION The implantable cardioverter defibrillator ( ICD ) is commonly used to treat patients with documented sustained ventricular tachycardia ( VT ) or ventricular fibrillation ( VF ) . Arrhythmia recurrence rates in these patients are high , but which patients will receive a therapy and the forms of arrhythmia recurrence ( VT or VF ) are poorly understood . METHODS AND RESULTS The therapy delivered by the ICD was examined in 449 patients r and omized to ICD therapy in the Antiarrhythmics Versus Implantable Defibrillators ( AVID ) Trial . Events triggering ICD shocks or antitachycardia pacing ( ATP ) were review ed for arrhythmia diagnosis , clinical symptoms , activity at the onset of the arrhythmia , and appropriateness and results of therapy . Both shock and ATP therapies were frequent by 2 years , with 68 % of patients receiving some therapy or having an arrhythmic death . An appropriate shock was delivered in 53 % of patients , and ATP was delivered in 68 % of patients who had ATP activated . The first arrhythmia treated in follow-up was diagnosed as VT ( 63 % ) , VF ( 13 % ) , supraventricular tachycardia ( 18 % ) , unknown arrhythmia ( 3 % ) , or due to ICD malfunction or inappropriate sensing ( 3 % ) . Acceleration of an arrhythmia by the ICD occurred in 8 % of patients who received any therapy . No physical activity consistently preceded arrhythmias , nor did any single clinical factor predict the symptoms of the arrhythmia . CONCLUSION Delivery of ICD therapy in AVID patients was common , primarily due to VT . Inappropriate ICD therapy occurred frequently . Use of ICD therapy as a surrogate endpoint for death in clinical trials should be avoided Background —Implantable cardioverter defibrillators ( ICDs ) reduce mortality in primary and secondary prevention .  Quality of life , mortality , appropriate therapies for specific ventricular rhythms , and inappropriate therapies for supraventricular tachycardia ( SVT ) were compared among 582 patients ( primary prevention=248 ; secondary prevention=334 ) in PainFREE Rx II , a 634-patient prospect i ve , r and omized study of antitachycardia pacing or shocks for fast ventricular tachycardia ( FVT ) . Methods and Results —ICDs were programmed identically with 3 zones ( ventricular tachycardia [ VT ] < 188 bpm ; FVT=188 to 250 bpm ; ventricular fibrillation [ VF ] > 250 bpm ) but r and omized to antitachycardia pacing or shock as initial therapy for FVT . All treated episodes with electrograms were adjudicated . Primary prevention patients had lower ejection fractions and more coronary artery disease . β-Blocker use , antiarrhythmic drug use , and follow-up duration were similar . Over 11±3 months , 1563 treated episodes were classified as VT ( n=740 ) , FVT ( n=350 ) , VF ( n=77 ) , and SVT ( n=396 ) . The distribution of VT , FVT , and VF was not different between primary and secondary prevention patients ( respectively , VT 52 % versus 54 % , FVT 35 % versus 35 % , and VF 14 % versus 10 % ) . More secondary prevention patients had appropriate therapies ( 26 % versus 18 % , P=0.02 ) , but among these patients , the median number of episodes per patient was similar . Inappropriate therapies occurred in 15 % of both groups and accounted for similar proportions of all detected and treated episodes ( 46 % in primary prevention patients versus 34 % in secondary prevention patients , P=0.09 ) . Quality of life improved modestly in both groups , and mortality was similar . Conclusions — Primary prevention patients are slightly less likely to have appropriate therapies than secondary prevention patients , but episode density is similar among patients with appropriate therapies . SVT result ed in more than one third of therapies in both groups , but quality of life and mortality were similar Reproduction of  spontaneously occurring ventricular tachycardia ( VT ) and induction of previously undocumented VT were studied prospect ively in 98 patients : 48 with documented sustained VT or ventricular fibrillation , 25 with nonsustained or exercise-induced VT , and 25 with no documented VT . Patients received 1 to 4 ventricular extrastimuli and ventricular burst pacing at 2 right ventricular ( RV ) sites , first at twice late diastolic threshold , and then at 10 mA using a prospect i ve , t and em study design . Spontaneously occurring VT was reproduced in 37 of 48 patients ( 77 % ) at twice late diastolic threshold and in 1 other patient ( 2 % ) at 10 mA. VT was reproduced at both RV sites in 17 of 48 patients ( 35 % ) and at 1 site in 20 of 48 patients ( 42 % ) at twice late diastolic threshold . A previously undocumented VT was induced in 7 of 25 patients ( 28 % ) with no documented VT at twice diastolic threshold and 14 of 25 patients ( 56 % ) at 10 mA. A previously undocumented VT was induced in 33 of 73 patients ( 45 % ) with a history of sustained or nonsustained VT at twice late diastolic threshold and in 47 of 73 patients ( 64 % ) at 10 mA. In patients with documented sustained VT , the use of up to 4 ventricular extrastimuli at multiple RV sites increases the sensitivity of the test . In patients without documented VT , the induction of previously undocumented VT with more than 3 ventricular extrastimuli limits the specificity of the test . Increased current provides only a slight advantage over 4 ventricular extrastimuli at twice late diastolic threshold in terms of reproduction of spontaneously occurring VT , but leads to a marked increase in induction of previously undocumented VT
Noninducibility of VT after VT ablation is associated with improved arrhythmia-free survival and all-cause mortality
BACKGROUND Although ventricular tachycardia ( VT ) ablation is a widely used therapy for patients with VT , the ideal end points for this procedure are not well defined .
We performed a meta- analysis of the published literature to assess the predictive value of noninducibility of postinfa rct ion VT for long-term outcomes after VT ablation .