title: Elimination of Local Abnormal Ventricular Activities: A New End Point for Substrate Modification in Patients With Scar-Related Ventricular Tachycardia Prophylactic catheter ablation for the prevention of defibrillator therapy. A prospective comparison of triple extrastimuli and left ventricular stimulation in studies of ventricular tachycardia induction. Treatment of ventricular tachycardia by transcatheter radiofrequency ablation in patients with ischemic heart disease. Cost-effectiveness of catheter ablation in patients with ventricular tachycardia. Effect of increased current, multiple pacing sites and number of extrastimuli on induction of 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 Completeness of reporting of trials published in languages other than English: implications for conduct and reporting of systematic reviews Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial
abstract: 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 For patients who have a ventricular tachyarrhythmic event , implantable cardioverter-defibrillators ( ICDs ) are a mainstay of therapy to prevent sudden death . However , ICD shocks are painful , can result in clinical depression , and do not offer complete protection against death from arrhythmia . We design ed this r and omized trial to examine whether prophylactic radiofrequency catheter ablation of arrhythmogenic ventricular tissue would reduce the incidence of ICD therapy . METHODS Eligible patients with a history of a myocardial infa rct ion underwent defibrillator implantation for spontaneous ventricular tachycardia or fibrillation . The patients did not receive  antiarrhythmic drugs .  Patients were r and omly assigned to  defibrillator implantation alone or defibrillator implantation with adjunctive catheter ablation  ( 64 patients in each group ) . Ablation was performed with the use of a substrate-based approach in which the myocardial scar is mapped and ablated while the heart remains predominantly in sinus rhythm . The primary end point was survival free from any appropriate ICD therapy . RESULTS The mortality rate 30 days after ablation was zero , and there were no significant changes in ventricular function or functional class during the mean ( + /-SD ) follow-up period of 22.5+/-5.5 months . Twenty-one patients assigned to defibrillator implantation alone ( 33 % ) and eight patients assigned to defibrillator implantation plus ablation ( 12 % ) received appropriate ICD therapy ( antitachycardia pacing or shocks ) ( hazard ratio in the ablation group , 0.35 ; 95 % confidence interval , 0.15 to 0.78 , P=0.007 ) . Among these patients , 20 in the control group ( 31 % ) and 6 in the ablation group ( 9 % ) received shocks ( P=0.003 ) . Mortality was not increased in the group assigned to ablation as compared with the control group ( 9 % vs. 17 % , P=0.29 ) . CONCLUSIONS In this r and omized trial , prophylactic substrate-based catheter ablation reduced the incidence of ICD therapy in patients with a history of myocardial infa rct ion who received ICDs for the secondary prevention of sudden death . ( Current Controlled Trials number , IS RCT N62488166 [ controlled-trials.com ] . ) One hundred and one patients with sustained unimorphic ventricular tachycardia underwent programmed ventricular stimulation with one of two protocol s. Fifty patients underwent programmed stimulation with protocol A , which consisted of burst overdrive pacing , single , double , and triple extrastimuli at the right ventricular apex , right ventricular outflow tract , or septum , and then at the left ventricular apex . Fifty-one patients underwent programmed stimulation with protocol B  , which consisted of burst overdrive pacing , single and double extrastimuli at the right ventricular apex , right ventricular outflow tract or septum , and at the left ventricular apex , followed by triple extrastimuli at these sites . The stimulation protocol was continued until sustained ventricular tachycardia or rapid , polymorphic ventricular tachycardia greater than 10 sec in duration was induced . With protocol A , clinical and non clinical ventricular tachycardia was induced in 76 % and 36 % of patients , respectively ; with protocol B , clinical and non clinical ventricular tachycardia was induced in 85 % and 38 % of patients , respectively . Direct-current countershock for sustained polymorphic ventricular tachycardia was required in 10 % of patients studied under protocol A , compared with in 2 % of patients studied under protocol B. With protocol A , near-maximal yield of induced clinical ( 72 % ) and non clinical ventricular tachycardia ( 30 % ) was attained after the use of triple extrastimuli at the first stimulation site . The yield of stimulation at a second right ventricular site and of left ventricular stimulation was only an additional 2 % each . With protocol B , triple extrastimuli increased the yield of induced clinical ventricular tachycardia from 61 % to 85 % . ( ABSTRACT TRUNCATED AT 250 WORDS 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 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 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 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 Lately , the number of systematic review s published has increased substantially . Many systematic review s exclude trials published in language s other than English . However , there is little empirical evidence to support this action . We looked for differences in the completeness of reporting between trials published in other language s and those published in English , to see whether the exclusion of trials published in other language s is justified . METHODS We compared completeness of reporting , design characteristics , and analytical approaches of 133 r and omised controlled trials ( RCTs ) published in English between 1989 and 1994 and 96 published in French , German , Italian , or Spanish during the same time . RCTs were identified by h and search ing of journals ( seven in English and six in the other language s ) . FINDINGS We found no significant differences between trials published in English and other- language trials for any single item in the completeness of reporting scale ( r and omisation , double-blinding , withdrawals ) , or for the overall score ( percentage of maximum possible score 51.0 % for trials in English , 46.2 % for trials in other language s ; 95 % CI for difference -1.1 to 10.5 ) . Other- language trials were more likely than English- language trials to have adult participants , to use two or more interventions , and to compare two or more active treatments without an untreated control group . Trials in other language s were less likely to report a clearly prespecified primary outcome or any rationale for sample size estimation . INTERPRETATION These results provide evidence for inclusion of all trial reports , irrespective of the language in which they are published , in systematic review s. Their inclusion is likely to increase precision and may reduce systematic errors . We hope that our findings will prove useful to those developing guidelines and policies for the conduct of reporting of systematic review 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
target: Noninducibility of VT after VT ablation is associated with improved arrhythmia-free survival and all-cause mortality
background: 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 .