Elimination of Local Abnormal Ventricular Activities: A New End Point for Substrate Modification in Patients With Scar-Related Ventricular Tachycardia Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial Treatment of ventricular tachycardia by transcatheter radiofrequency ablation in patients with ischemic heart disease. 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 Incidence and predictors of major complications from contemporary catheter ablation to treat cardiac arrhythmias. Cost-effectiveness of catheter ablation in patients with ventricular tachycardia. Left Ventricular Remodeling and Ventricular Arrhythmias After Myocardial Infarction The 1+1 Trial: A Prospective Trial of a Dual- Versus a Single-Chamber Implantable Defibrillator in Patients With Slow Ventricular Tachycardias Factors influencing appropriate firing of the implanted defibrillator for ventricular tachycardia/fibrillation: findings from the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II). Designation and distribution of events in the Multicenter UnSustained Tachycardia Trial (MUSTT). Out-of-hospital cardiac arrest survival improving over time: Results from the Resuscitation Outcomes Consortium (ROC). Prevention of Fatal Arrhythmias in High-Risk Subjects by Fish Oil n-3 Fatty Acid Intake Incidence and prognostic significance of sustained ventricular tachycardias in heart failure patients implanted with biventricular pacemakers without a back-up defibrillator: results from the prospective, multicentre, Mona Lisa cohort study. Effect of increased current, multiple pacing sites and number of extrastimuli on induction of ventricular tachycardia. Cardiovascular magnetic resonance, fibrosis, and prognosis in dilated cardiomyopathy. Beta-blocker use and survival in patients with ventricular fibrillation or symptomatic ventricular tachycardia: the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial. Relationship of reverse anatomical remodeling and ventricular arrhythmias after cardiac resynchronization. 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. Randomized controlled study of detection enhancements versus rate-only detection to prevent inappropriate therapy in a dual-chamber implantable cardioverter-defibrillator. Effect of fish oil on ventricular tachyarrhythmia and death in patients with implantable cardioverter defibrillators: the Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) randomized trial. Fish oil supplementation and risk of ventricular tachycardia and ventricular fibrillation in patients with implantable defibrillators: a randomized controlled trial. Should everyone with an ejection fraction less than or equal to 30% receive an implantable cardioverter-defibrillator? Not everyone with an ejection fraction < or = 30% should receive an implantable cardioverter-defibrillator. Analysis of implantable cardioverter defibrillator therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial.
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 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 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 — 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 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 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 Background —The relation between left ventricular ( LV ) remodeling and ventricular arrhythmias after myocardial infa rct ion is poorly documented . We investigated the relations between LV size , hypertrophy , and function and ventricular arrhythmias in 263 patients from the Survival and Ventricular Enlargement ( SAVE ) study , using quantitative 2D echocardiography and ambulatory ECG monitoring after myocardial infa rct ion . Methods and Results —Transthoracic 2D echocardiograms and arrhythmia monitoring were performed at baseline ( mean , 11 days ) and 1 and 2 years after infa rct ion . LV size , short-axis muscle ( mass ) area ( LVMA ) , and function were quantified from 2D echocardiograms . The prevalence of ventricular tachycardia ( VT ) and frequent ventricular ectopy ( premature ventricular contractions [ PVCs ] > 10/h ) was assessed from ambulatory ECG . VT and PVCs > 10/h occurred in 20 % and 29 % of patients at baseline , in 22 % and 35 % at 1 year and 23 % and 39 % at 2 years , respectively . VT and PVCs > 10/h at baseline and 1 and 2 years were significantly related to LV size , LVMA , and function . Furthermore , changes in LV size and function from baseline to 2 years predicted both VT and PVCs > 10/h . The study was underpowered to detect treatment effect of ACE inhibitors and & bgr;-adrenergic receptor blockers but did not alter the relations between ventricular arrhythmias , LV size , and function . Conclusions —Quantitative echocardiographic assessment of LV size , LVMA , and function and changes in these measurements over time predict ventricular arrhythmias after infa rct ion . Altered LV architecture and function during postinfa rct ion LV remodeling provide an important substrate for triggering high- grade ventricular arrhythmias 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 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 Patients with coronary artery disease , depressed left ventricular ejection fraction , and nonsustained ventricular tachycardia ( VT ) have a high mortality rate due to arrhythmic ( arrhythmic death/cardiac arrest ) and other cardiac causes . The Multicenter UnSustained Tachycardia Trial ( MUSTT ) investigated whether electrophysiologic study ( EPS ) was helpful in choosing drug or defibrillator therapy in patients induced into sustained VT . The events committee attempted to categorize follow-up events in patients in MUSTT and to present a detailed breakdown of events . A derivative of the Hinkle-Thaler classification was used , incorporating lessons from other multicenter studies . The committee was blinded to results of EPS and implantable cardioverter-defibrillator ( ICD ) or other antiarrhythmic therapy status of patients . The primary end point was cardiac arrest or death from arrhythmia . Secondary end points were death from all causes , cardiac causes , and spontaneous sustained VT . Classifications were death and cardiac arrest . Each was similarly divided as arrhythmic with 14 subcategories , e.g. , unwitnessed or related to EPS and nonarrhythmic with 10 subcategories , e.g. , ischemia . Terminal VF in progressive heart failure was considered nonarrhythmic . Events were review ed by 2 members . Disagreements were resolved by the 2 members or , if needed , by the full committee . Of the 2,202 patients in MUSTT , there were 902 deaths . Sustained VT  requiring cardioversion occurred in 182 patients . An additional 94 patients had resuscitated cardiac arrests .  Events occurred in 1,027 patients , and all were review ed . The 3 leading events were deaths that were classed as sudden/unwitnessed ( 23 % of 902 ) , due to progressive heart failure ( 22 % ) , or due to noncardiovascular causes ( 18 % ) . Arrhythmic deaths or cardiac arrests were highest in inducible patients r and omized to no antiarrhythmic therapy ; next were inducible patients receiving an ICD ; and lowest were in patients who were noninducible . In conclusion , the classification system provided a detailed breakdown of events in consistent categories , showing utility for event analysis and interpretation and development of therapeutic strategies . The classifications assigned by the committee were used in all MUSTT outcomes reports , thus affecting all reported outcomes and overall interpretations of the MUSTT BACKGROUND Out-of-hospital cardiac arrest ( OHCA ) remains a leading cause of death and a 2010 meta- analysis concluded that outcomes have not improved over several decades . However , guidelines have changed to emphasize CPR quality , minimization of interruptions , and st and ardized post-resuscitation care . We sought to evaluate whether OHCA outcomes have improved over time among agencies participating in the Resuscitation Outcomes Consortium ( ROC ) cardiac arrest registry ( Epistry ) and r and omized clinical trials ( RCTs ) . METHODS Observational cohort study of 47,148 EMS-treated OHCA cases in Epistry from 139 EMS agencies at 10 ROC sites that participated in at least one RCT between 1/1/2006 and 12/31/2010 . We review ed patient , scene , event characteristics , and outcomes of EMS-treated OHCA over time , including subgroups with initial rhythm of pulseless ventricular tachycardia or ventricular fibrillation ( VT/VF ) . RESULTS Mean response interval , median age and male proportion remained similar over time . Unadjusted survival to discharge increased between 2006 and 2010 for treated OHCA ( from 8.2 % to 10.4 % ) , as well as for subgroups of VT/VF ( 21.4 % to 29.3 % ) and byst and er witnessed VT/VF ( 23.5 % to 30.3 % ) . Compared with 2006 , adjusted survival to discharge was significantly higher in 2010 for treated cases ( OR = 1.72 ; 95 % CI 1.53 , 1.94 ) , VT/VF cases ( OR = 1.69 ; 95 % CI 1.45 , 1.98 ) and byst and er witnessed VT/VF cases ( OR = 1.65 ; 95 % CI 1.36 , 2.00 ) . Tests for trend in each subgroup were significant ( p < 0.001 ) . CONCLUSIONS ROC-wide survival increased significantly between 2006 and 2010 . Additional research efforts are warranted to identify specific factors associated with this improvement Background — The long-chain n-3 fatty acids in fish have been demonstrated to have antiarrhythmic properties in experimental models and to prevent sudden cardiac death in a r and omized trial of post – myocardial infa rct ion patients . Therefore , we hypothesized that these n-3 fatty acids might prevent potentially fatal ventricular arrhythmias in high-risk patients . Methods and Results — Four hundred two patients with implanted cardioverter/defibrillators ( ICDs ) were r and omly assigned to double-blind treatment with either a fish oil or an olive oil daily supplement for 12 months . The primary end point , time to first ICD event for ventricular tachycardia or fibrillation ( VT or VF ) confirmed by stored electrograms or death from any cause , was analyzed by intention to treat . Secondary analyses were performed for “ probable ” ventricular arrhythmias , “ on-treatment ” analyses for all subjects who had taken any of their oil supplements , and “ on-treatment ” analyses only of those subjects who were on treatment for at least 11 months . Compliance with double-blind treatment was similar in the 2 groups ; however , the noncompliance rate was high ( 35 % of all enrollees ) . In the primary analysis , assignment to treatment with the fish oil supplement showed a trend toward a prolonged time to the first ICD event ( VT or VF ) or of death from any cause ( risk reduction of 28 % ; P=0.057 ) . When therapies for probable episodes of VT or VF were included , the risk reduction became significant at 31 % ; P=0.033 . For those who stayed on protocol for at least 11 months , the antiarrhythmic benefit of fish oil was improved for those with confirmed events ( risk reduction of 38 % ; P=0.034 ) . Conclusions — Although significance was not achieved for the primary end point , this study provides evidence that for individuals at high risk of fatal ventricular arrhythmias , regular daily ingestion of fish oil fatty acids may significantly reduce potentially fatal ventricular arrhythmias AIMS The aim of this study was to investigate the 12-month incidence , predictive factors , and prognosis of sustained ventricular tachycardia ( VT ) in chronic heart failure patients implanted with biventricular pacemakers without a back-up defibrillator ( CRT-P ) , assessed by continuous intracardiac ventricular electrograms . METHODS AND RESULTS The Mona Lisa study , a prospect i ve , multicentre , cohort study , design ed to determine the incidence of sustained VT and its prognostic impact in CRT-P recipients within the year after implant enrolled 198 patients with moderate or severe chronic heart failure , despite optimal pharmacological therapy .  An independent committee review ed the data from all arrhythmic episodes as well as causes of death according to predefined criteria . During a mean follow-up of 9.8 + /- 3.1 months after implantation , 8 patients experienced at least one episode of sustained VT [ 4.3 % ; 95 % confidence interval ( CI ) , 1.1 - 7.5 ] and 21 deaths occurred , giving a 12-month mortality rate of 11.7 % ( 95 % CI , 6.4 - 16.9 ) . The presence of sustained VT was associated with a high risk of sudden cardiac death ( SCD ) and the lowest 12-month overall survival ( P < 0.0001 ) . CONCLUSION The incidence of sustained VT remains relatively low in the first year after CRT-P implantation , but when present appears closely associated with short-term adverse outcomes , especially SCD . This emphasizes the possible value of remote monitoring to detect high-risk patients for urgent upgrading 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 OBJECTIVES We studied the prognostic implication s of midwall fibrosis in dilated cardiomyopathy ( DCM ) in a prospect i ve longitudinal study . BACKGROUND Risk stratification of patients with nonischemic DCM in the era of device implantation is problematic . Approximately 30 % of patients with DCM have midwall fibrosis as detected by late gadolinium-enhancement ( LGE ) cardiovascular magnetic resonance ( CMR ) , which may increase susceptibility to arrhythmia and progression of heart failure . METHODS Consecutive DCM patients ( n = 101 ) with the presence or absence of midwall fibrosis  were followed up prospect ively for 658 + /- 355 days for events . RESULTS Midwall fibrosis was present in 35 % of patients and was associated with a higher rate of the predefined primary combined end point of all-cause death and hospitalization for a cardiovascular event ( hazard ratio 3.4 , p = 0.01 ) . Multivariate analysis showed midwall fibrosis as the sole significant predictor of death or hospitalization . However , there was no significant difference in all-cause mortality between the 2 groups . Midwall fibrosis also predicted secondary outcome measures of sudden cardiac death ( SCD ) or ventricular tachycardia ( VT ) ( hazard ratio 5.2 , p = 0.03 ) . Midwall fibrosis remained predictive of SCD/VT after correction for baseline differences in left ventricular ejection fraction between the 2 groups . CONCLUSIONS In DCM , midwall fibrosis determined by CMR is a predictor of the combined end point of all-cause mortality and cardiovascular hospitalization , which is independent of ventricular remodeling . In addition , midwall fibrosis by CMR predicts SCD/VT . This suggests a potential role for CMR in the risk stratification of patients with DCM , which may have value in determining the need for device therapy OBJECTIVES To evaluate whether use of beta-adrenergic blocking agents , alone or in combination with specific antiarrhythmic therapy , is associated with improved survival in persons with ventricular fibrillation ( VF ) or symptomatic ventricular tachycardia ( VT ) . BACKGROUND The ability of beta-blockers to alter the mortality of patients with VF or VT receiving contemporary medical management is not well defined . METHODS Survival of 1,016 r and omized and 2,101 eligible , nonr and omized patients with VF or symptomatic VT followed in the Antiarrhythmics Versus Implantable Defibrillators ( AVID ) trial through December 31 , 1996 was assessed using Cox proportional hazards analysis . RESULTS The 817 ( 28 % ) patients discharged from hospital receiving beta-blockers  had less ventricular dysfunction , fewer symptoms of heart failure and a different pattern of medication use compared with patients not receiving beta-blockers . Before adjustment for important prognostic variables , beta-blockade was not significantly associated with survival in r and omized or in eligible , nonr and omized patients treated with specific antiarrhythmic therapy . After adjustment , beta-blockade remained unrelated to survival in r and omized or in eligible , nonr and omized patients treated with amiodarone alone ( n = 1142 ; adjusted relative risk [ RR ] = 0.96 ; 95 % confidence interval [ CI ] 0.64 - 1.45 ; p = 0.85 ) or a defibrillator alone ( n = 1347 ; adjusted RR = 0.88 ; 95 % CI 0.55 to 1.40 ; p = 0.58 ) . In contrast , beta-blockade was independently associated with improved survival in eligible , nonr and omized patients who were not treated with specific antiarrhythmic therapy ( n = 412 ; adjusted RR = 0.47 ; 95 % CI 0.25 to 0.88 ; p = 0.018 ) . CONCLUSIONS Beta-blocker use was independently associated with improved survival in patients with VF or symptomatic VT who were not treated with specific antiarrhythmic therapy , but a protective effect was not prominent in patients already receiving amiodarone or a defibrillator INTRODUCTION Cardiac resynchronization ( CRT ) affects reverse anatomical remodeling in patients with heart failure .  CRT has also been associated with fewer ventricular arrhythmias and reduced sudden death in some clinical trials , but the predictors and mechanism of the antiarrhythmic actions of CRT have not been well defined . The purpose of this study is to investigate the relationship of reverse anatomical remodeling to ventricular arrhythmias in CRT patients . METHODS AND RESULTS A retrospective analysis was performed of the InSync III Marquis study , a prospect i ve , r and omized , multicenter CRT trial . Echocardiographic data from 198 patients were obtained at baseline and after 6 months of CRT , and anatomical responders were defined as a reduction in left ventricular end systolic volume ( LVESV ) of > or=15 % . Anatomical responders ( n = 71 , 36 % ) demonstrated 29 % fewer single premature ventricular contractions beats ( PVCs ) ( P = 0.0001 ) , 48 % fewer PVC runs ( p = 0.0096 ) , and fewer treated episodes of ventricular tachycardia or fibrillation ( VT/VF ) ( P = 0.050 ) than nonresponders . Multiple regression analysis demonstrated that responder status significantly predicted single PVCs and PVC runs . Gender was the most important predictor of treated VT/VF with females having no episodes over 6 months of follow-up . CONCLUSIONS Anatomic responders to CRT demonstrate significantly fewer single PVCs and runs of PVCs . The implication of these observations is that anatomic remodeling is linked to electrical remodeling 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 ) 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 CONTEXT Very-long-chain n-3 polyunsaturated fatty acids ( omega-3 PUFAs ) from fish are thought to reduce risk of sudden death , possibly by reducing susceptibility to cardiac arrhythmia . OBJECTIVE To study the effect of supplemental fish oil vs placebo on ventricular tachyarrhythmia or death . DESIGN , SETTING , AND PATIENTS The Study on Omega-3 Fatty acids and ventricular Arrhythmia ( SOFA ) was a r and omized , parallel , placebo-controlled , double-blind trial conducted at 26 cardiology clinics across Europe . A total of 546 patients with implantable cardioverter-defibrillators ( ICDs ) and prior documented malignant ventricular tachycardia ( VT ) or ventricular fibrillation ( VF ) were enrolled between October 2001 and August 2004 . Patients were r and omly assigned to receive 2 g/d of fish oil ( n = 273 ) or placebo ( n = 273 ) for a median period of 356 days ( range , 14 - 379 days ) . MAIN OUTCOME MEASURE Appropriate ICD intervention for VT or VF , or all-cause death . RESULTS The primary end point occurred in 81 ( 30 % ) patients taking fish oil vs 90 ( 33 % ) patients taking placebo ( hazard ratio [ HR ] , 0.86 ; 95 % confidence interval [ CI ] , 0.64 - 1.16 ; P = .33 ) . In prespecified subgroup analyses , the HR was 0.91 ( 95 % CI , 0.66 - 1.26 ) for fish oil vs placebo in the 411 patients who had experienced VT in the year before the study , and 0.76 ( 95 % CI , 0.52 - 1.11 ) for 332 patients with prior myocardial infa rct ions . CONCLUSION Our findings do not indicate evidence of a strong protective effect of intake of omega-3 PUFAs from fish oil against ventricular arrhythmia in patients with ICDs . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00110838 CONTEXT Clinical studies of omega-3 polyunsaturated fatty acids ( PUFAs ) have shown a reduction in sudden cardiac death , suggesting that omega-3 PUFAs may have antiarrhythmic effects . OBJECTIVE To determine whether omega-3 PUFAs have beneficial antiarrhythmic effects in patients with a history of sustained ventricular tachycardia ( VT ) or ventricular fibrillation ( VF ) . DESIGN AND SETTING R and omized , double-blind , placebo-controlled trial performed at 6 US medical centers with enrollment from February 1999 until January 2003 . PATIENTS Two hundred patients with an implantable cardioverter defibrillator ( ICD ) and a recent episode of sustained VT or VF . INTERVENTION Patients were r and omly assigned to receive fish oil , 1.8 g/d , 72 % omega-3 PUFAs , or placebo and were followed up for a median of 718 days ( range , 20 - 828 days ) . MAIN OUTCOME MEASURES Time to first episode of ICD treatment for VT/VF , changes in red blood cell concentrations of omega-3 PUFAs , frequency of recurrent VT/VF events , and predetermined subgroup analyses . RESULTS Patients r and omized to receive fish oil had an increase in the mean percentage of omega-3 PUFAs in red blood cell membranes from 4.7 % to 8.3 % ( P<.001 ) , with no change observed in patients receiving placebo . At 6 , 12 , and 24 months , 46 % ( SE , 5 % ) , 51 % ( 5 % ) , and 65 % ( 5 % ) of patients r and omized to receive fish oil had ICD therapy for VT/VF compared with 36 % ( 5 % ) , 41 % ( 5 % ) , and 59 % ( 5 % ) for patients r and omized to receive placebo ( P = .19 ) . In the subset of 133 patients whose qualifying arrhythmia was VT , 61 % ( SE , 6 % ) , 66 % ( 6 % ) , and 79 % ( 6 % ) of patients in the fish oil group had VT/VF at 6 , 12 , and 24 months compared with 37 % ( 6 % ) , 43 % ( 6 % ) , and 65 % ( 6 % ) of patients in the control group ( P = .007 ) . Recurrent VT/VF events were more common in patients r and omized to receive fish oil ( P<.001 ) . CONCLUSION Among patients with a recent episode of sustained ventricular arrhythmia and an ICD , fish oil supplementation does not reduce the risk of VT/VF and may be proarrhythmic in some patients Although the total number of deaths attributed to cardiovascular disease has decreased during recent decades , an increase in the percentage of cardiac deaths occurring suddenly ( from 56 % in 1989 to 63 % in 1998 ) has actually result ed in an increase in the total number of sudden deaths in the United States.1 The problem of sudden death spans all racial and cultural groups and is equally important in men and women . It is now 40 years since continuous ECG monitoring revealed that ventricular tachycardia and ventricular fibrillation ( VT/VF ) are responsible for the majority of sudden deaths . Dissemination of this information result ed in a marked change in practice . Until the 1970s , physicians treated only symptomatic VTs . Therapeutic options were limited to a few antiarrhythmic drugs , administered empirically . With the advent of telemetric ECG monitoring and continuous ambulatory ( Holter ) ECG monitoring came the recognition that frequent and multiform ventricular ectopy often preceded episodes of VF in the acute phase of myocardial infa rct ion ( MI ) . Ventricular ectopy and nonsustained VT was documented 1 to 2 weeks after MI in many patients . The presence of frequent ventricular premature complexes and runs of nonsustained VT in patients with significant left ventricular dysfunction were then demonstrated to be an independent predictor of sudden cardiac death late after MI . This information then led to the practice of administering antiarrhythmic drugs to suppress ventricular ectopy under the presumption that suppression of asymptomatic ectopy would prevent sudden death . This fashion lasted almost 20 years , until the results of the Cardiac Arrhythmia Suppression Trial ( CAST ) trial demonstrated the harm caused by this approach.2 Thus , a sea change in the practice of cardiology had occurred , from treating only symptomatic patients to therapy aim ed at primary prevention of sudden death . The initial efforts using antiarrhythmic drugs failed to reduce mortality . While many physicians in the 1970s were administering prophylactic drugs to survivors of MI , Michel Mirowski was developing the implantable cardioverter-defibrillator ( ICD ) , introduced to clinical medicine in 1980.3 It took more than a decade before r and omized , controlled trials evaluating the ability of ICDs to reduce mortality in survivors of cardiac arrest or sustained VT appeared in print . These studies demonstrated the superiority of ICDs over amiodarone and other pharmacological agents for secondary prevention of sudden death in survivors of cardiac arrest.4–7 After publication of the secondary -prevention studies , 3 trials were published demonstrating that ICDs could reduce mortality in patients with chronic coronary disease 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
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 .