Ventricular Tachycardia Ablation In Patients Research Articles

Current practice of ventricular tachycardia ablation in patients with implantable cardioverter-defibrillators

We performed a survey on current practice of ventricular tachycardia (VT) ablation in patients with implantable cardioverter-defibrillators among the European Heart Rhythm Association Research Network. The main indication for the procedure is the occurrence of multiple shocks or electrical storm, while prophylactic ablation is only rarely performed. The epicardial approach is seldom used and mostly only after failure of endocardial ablation. The main ablation strategy is targeting the clinical VT only by substrate mapping and ablation, and by targeting fractionated potentials with utilization of modern electroanatomical mapping systems. Still, a considerable number of centres frequently perform the procedure using conventional mapping catheters only.

Ventricular Tachycardia Ablation in Patients with HeartMate II Left Ventricular Assist Devices: Rhythm Still Matters in the Bionic Age

Ventricular Tachycardia Ablation in Patients with HeartMate II Left Ventricular Assist Devices: Rhythm Still Matters in the Bionic Age

Ventricular Tachycardia Ablation Remains Treatment of Last Resort in Structural Heart Disease: Argument for Earlier Intervention

Despite advances in ablation of ventricular tachycardia (VT), recognized toxicity of amiodarone, and potential harm of implantable cardioverter defibrillator (ICD) shocks, there appears to be reluctance to pursue catheter ablation. We tested the hypothesis that patients with structural heart disease and VT are referred late for ablation and may have worse outcomes as a result. Consecutive patients with VT and structural heart disease referred to a single center, between January 2008 and April 2009 were studied. Patients with prior VT ablations were excluded. Late referrals were defined as those with 2 or more episodes of VT, separated by at least 1 month. Ninety-eight consecutive patients were analyzed. Ninety-six percent of patients had an ICD implanted prior to ablation, 58% were in VT storm and 67% taking ≥400 mg daily of amiodarone or amiodarone intolerant (10%). Thirty-six patients fit the definition of early referral and 62 late. Overall acute procedural success was achieved in 89%. Amiodarone dose decreased from a mean and median of 559 and 400 mg daily preablation to 98 and 0 postablation (P < 0.01). Mean and median VT episodes decreased from 17 and 6 in the month preceding ablation to 1 and 0 in the 6 months following ablation (P < 0.01). In Kaplan-Meier analysis, the early referral group had superior 1-year VT free survival (P = 0.01). VT ablation is frequently reserved for patients receiving recurrent ICD shocks despite high dose amiodarone. Stronger consideration should be given to earlier referral for VT ablation in patients with structural heart disease.

Isolated Potentials and Pace‐Mapping as Guides for Ablation of Ventricular Tachycardia in Various Types of Nonischemic Cardiomyopathy

In patients with prior infarction, isolated potentials (IPs) during sinus rhythm reflect fixed scar and often indicate sites critical for ventricular tachycardia (VT). The purpose of this study was to determine the value of IPs in conjunction with pace-mapping to guide VT ablation in patients with various types of nonischemic cardiomyopathy. Mapping and ablation of VT were performed in 35 consecutive patients (26 men, age 55 ± 13 years, ejection fraction 0.31 ± 0.14) with VT and various etiologies of nonischemic cardiomyopathy. Pace-mapping was performed at sites with low voltage. Radiofrequency energy was delivered at sites with concealed entrainment or matching pace-maps. One hundred ninety-five VTs (mean cycle length 363 ± 88 ms) were induced. Sites with prespecified ablation criteria displaying IPs during sinus rhythm were recorded in 21 of 35 patients (60%, IP-positive). In these patients, a total of 216 sites meeting prespecified ablation criteria were identified and 146 of 216 sites (68%) displayed IPs. Fifteen of 21 IP-positive patients (71%) no longer had inducible VT after ablation. In 14 of 35 patients, no sites with IPs where prespecified ablation criteria were met were identified (IP-negative) despite combined endocardial and epicardial mapping in 7 of 14 patients. Only 1 of 14 IP-negative patients (7%) no longer had inducible VT at the end of the ablation procedure. During a mean follow-up of 18 ± 13 months, 14 of 21 IP-positive patients (67%) remained arrhythmia-free, compared to 1 of 14 IP-negative patients (7%; P < 0.01). Half of the IP-negative patients had major adverse events due to recurrent arrhythmias, compared to none in IP-positive patients. IPs in conjunction with pace-mapping are helpful for identifying critical isthmus areas for ablation of VT in patients with various types of nonischemic cardiomyopathy. Patients with nonischemic cardiomyopathy in whom the arrhythmogenic substrate is characterized by IPs have a more favorable outcome than patients in whom IPs are absent.

Radiofrequency catheter ablation of ventricular arrhythmias in patients with hypertrophic cardiomyopathy: safety and feasibility

Management of ventricular tachycardia (VT) in patients with hypertrophic cardiomyopathy (HCM) is challenging. The purpose of this study is to assess the value of radiofrequency catheter ablation (RFCA) for the treatment of the VTs in the setting of HCM. Twenty-two patients (18 with ICD) with HCM and multiple episodes of VTs resistant to medical therapy underwent RFCA with an open irrigation catheter. Epicardial access was obtained if required. All patients were followed for at least 1 year after RFCA. Mean age was 50.4 +/- 15.3, and mean ejection fraction was 34.3% +/- 9.8%. RFCA was performed endocardially in all patients, while epicardial radiofrequency applications were needed in 13 patients. A previous endocardial ablation was unsuccessful in six patients. At 20 +/- 9 months of follow-up, elimination of VTs reached 73%. No major complication was observed during and after the procedures in all patients. Catheter ablation of VTs in patients with hypertrophic cardiomyopathy refractory to medical therapy is safe, feasible, and successful in eliminating VT. Epicardial VT mapping and ablation should be considered as an important access option for the treatment of these patients to increase the success rate.

Incidence and predictors of mortality following ablation of ventricular tachycardia in patients with an implantable cardioverter-defibrillator

Long-term outcomes following ablation of ventricular tachycardia (VT) have not been well described. The purpose of this study was to identify the incidence and predictors of mortality following catheter ablation of VT in patients with an implantable cardioverter-defibrillator (ICD). The cohort included in the analysis consisted of patients with ischemic or nonischemic cardiomyopathy undergoing electrophysiologic study and ablation of VT. Catheter ablation of VT involved the use of pacemapping, entrainment mapping (when possible), and substrate modification. Clinical recurrences, ICD therapy history, and mortality were recorded for all patients included in the cohort. Comparisons were made between those subjects who died over a 3-year follow-up period and those who survived. A total of 208 subjects underwent 327 VT ablations over the course of the study period. Sixty-seven deaths (75% of all deaths and 32% of the cohort) occurred within 3 years after VT ablation. After multivariable adjustment, clinical predictors of mortality included age, lower left ventricular ejection fraction, and presence of renal insufficiency. Procedural variables associated with reduced mortality following VT ablation included presence of hemodynamically tolerated VT, lack of inducibilty of any VT following ablation, and procedural date in the latter part of the study. The survival rate after VT ablation has improved over time and may reflect improved mapping and ablation techniques, in addition to improved therapies for treatment of congestive heart failure. Tolerated VT and lack of inducible ventricular arrhythmias following VT ablation was associated with improved survival in this study, suggesting their value as a risk factor for subsequent mortality.

Role of radiofrequency catheter ablation of ventricular tachycardia in cardiac sarcoidosis: Report from a multicenter registry

Management of ventricular tachycardia (VT) is challenging in patients with cardiac sarcoidosis. The purpose of this study was to assess the response of VT in patients with cardiac sarcoidosis to medical therapy and radiofrequency ablation. Forty-two patients with a diagnosis of cardiac sarcoidosis based on the Japanese Health Ministry criteria were followed. When VT occurred, a stepwise approach was used: implantable cardioverter-defibrillator placement, immunosuppressive agents, antiarrhythmic medications, then radiofrequency ablation. In nine patients (age 46.7 +/- 8.6 years; ejection fraction 42 +/- 14%), VT was not controlled by medical therapy, and radiofrequency ablation was performed. A total of 44 VTs (mean cycle length 348 +/- 78 ms) were induced. Endocardial radiofrequency ablation was performed in eight patients (right ventricular in 5, left ventricular in 3) and epicardial radiofrequency ablation in one patient. In 4 of 5 patients with right ventricular VTs, a peritricuspid circuit was identified. Critical areas were identified for 21 (48%) of 44 VTs, resulting in elimination of 31 (70%) of 44 VTs. The most frequent VT circuit was reentry in the peritricuspid area. This type of VT was eliminated in all patients. Arrhythmic events decreased from 271 +/- 363 episodes preablation to 4.0 +/- 9.7 postablation. All patients had either a decrease (n = 4) or complete elimination (n = 5) of VT during mean follow-up of 19.8 +/- 19.6 months. Catheter ablation of VT in patients with cardiac sarcoidosis refractory to medical therapy is effective in eliminating VT or markedly reducing the VT burden. The disease process in cardiac sarcoidosis often involves a specific area in the basal right ventricle predisposing to peritricuspid reentry.

Abstract 4088: Isolated Potentials and Pace-Mapping to Guide Ablation for Ventricular Tachycardia in Patients with Non-Ischemic Cardiomyopathy

Background : Isolated potentials (IPs) during sinus rhythm are indicators of fixed scar in patients with prior infarcts. IPs in conjunction with pace-mapping (PM) have been helpful to guide ablation of post-infarction ventricular tachycardia (VT). The purpose of this study was to determine the value of IPs in conjunction with PM to guide VT ablation in patients with non-ischemic cardiomyopathy. Methods : 32 consecutive patients (23 male, age 56±13 years, ejection fraction 0.30±0.14) with VT and non-ischemic cardiomyopathy were analyzed. Thirty/32 patients had an implanted cardioverter defibrillator (ICD). Electroanatomic maps of the left (n=21) and right ventricle (n=13), the coronary sinus (n=3), and the epicardium (n=4) were obtained during baseline rhythm. PM was performed at sites with low voltage (&lt;1.5mV). Radiofrequency energy was delivered at sites with concealed entrainment or matching pace-maps. Mean follow-up time was 10±9 months. Results : 173 VTs (cycle length 359±86 ms) were induced. Appropriate ablation sites with IPs during sinus rhythm were recorded in 19/32 patients (59%) (group A). In these patients, a total of 195 appropriate target sites were identified for 56/100 induced VTs (56%); 136/195 sites (70%) displayed IPs. In the remaining 13 patients, no target sites with IPs were identified (group B) despite combined endocardial and transcutaneous epicardial mapping in 3/13 patients. In these 13 patients, a total of 96 appropriate target sites were identified for 25/73 induced VTs (34%). Fifteen/19 patients (79%) in group A were non-inducible at the end of the procedure compared to 2/13 patients (15%) in group B. During a mean follow-up of 10±9 months, 15/19 patients (79%) in group A compared to 1/13 patients (8%) in group B remained arrhythmia free (p=0.0002). Conclusion : IPs in conjunction with PM are helpful in identifying critical isthmus areas for ablation of VT in patients with non-ischemic cardiomyopathy. Differences in the extent of fixed scar tissue may be the reason for differences in the prevalence of IPs, and this might explain better ablation results in some patients with non-ischemic cardiomyopathy.

Endocardial catheter ablation of ventricular tachycardia in patients with ventricular assist devices

The outcomes of patients with ventricular assist devices (VADs) who undergo catheter ablation for ventricular tachycardia (VT) have not been reported. The purpose of this study was to assess the feasibility, safety, and efficacy of endocardial VT ablation in patients with VADs. We retrospectively reviewed three cases at our institution where endocardial catheter ablation was performed in patients with VADs and incessant VT. Three patients with underlying cardiomyopathies and VADs underwent VT ablation for incessant VT refractory to multiple antiarrhythmic medications. In each case, VT was either eliminated or significantly ameliorated by catheter ablation. No procedure-related complications occurred. The hemodynamic stability afforded by the VAD played an important role in facilitating ablation in two of the cases. Catheter ablation for VT in VAD patients appears to be feasible, safe, and effective based on our initial experience. Several technical issues, such as decreases in ventricular volumes that can limit maneuverability of the ablation catheter and potential entrapment of the mapping catheter in the inflow cannula, need to be considered at the time of ablation.

Ablation of ventricular tachycardia in the setting of coronary artery disease.

Ablation of reentrant ventricular tachycardia (VT) is an accepted therapy for certain patients with VT caused by coronary artery disease (CAD). Its use is currently limited to patients with sustained, monomorphic, hemodynamically tolerated VT. The use of entrainment in mapping reentrant VT has made possible increasingly accurate localization of critical sites on the reentrant pathway that are amenable to ablation. Recent work has examined the accuracy with which various mapping criteria are able to predict successful ablation of reentrant VT in patients with CAD. Other recent studies have investigated attempted ablation of all inducible VTs in patients with multiple VT morphologies. In the future, substrate mapping may make possible ablation of VT in patients with nonsustained or fast, hemodynamically unstable VTs, thus allowing VT ablation to become a first-line therapy for many patients with VT in the setting of CAD.

Radiofrequency catheter ablation of ventricular tachycardia in patients with coronary artery disease.

Radiofrequency (RF) ablation of idiopathic ventricular tachycardia (VT) has been demonstrated to be highly efficacious, but the efficacy of RF ablation of VT in patients with coronary artery disease has been unknown. Therefore, the purpose of this study was to determine the feasibility of RF ablation of VT in patients with coronary artery disease. Fifteen consecutive patients with coronary artery disease and a history of myocardial infarction underwent an attempt at RF ablation of 16 hemodynamically stable monomorphic VTs that had been documented clinically on a 12-lead ECG and that had not been successfully managed by pharmacological or device therapy. One VT was incessant, five occurred more than 25 times, and the remainder occurred two to 20 times. An additional four VTs that had not been documented clinically also were targeted for ablation. The mean age of the patients was 68 +/- 7 years (+/- SD), and their mean left ventricular ejection fraction was 0.27 +/- 0.08. The mean cycle length of the 20 VTs targeted for ablation was 438 +/- 82 msec. Ablation sites were selected based on endocardial activation mapping, pace mapping, identification of an isolated mid-diastolic potential, or concealed entrainment. Sixteen of the 20 VTs (80%) were successfully ablated in 11 of 15 patients (73%), using a mean of 4.2 +/- 3 applications of RF energy, and no recurrences of the ablated VTs occurred during 9.1 +/- 3.3 months of follow-up. The mean duration of the ablation procedures was 128 +/- 30 minutes. No complications occurred in any of the patients. The results of this study demonstrate that RF ablation of hemodynamically stable VT is feasible as adjunctive therapy in selected patients with coronary artery disease.