Radiofrequency Catheter Ablation Of Ventricular Tachycardia Research Articles

Clinical Outcomes in Patients With Dilated Cardiomyopathy and Ventricular Tachycardia

BackgroundRecurrent ventricular tachycardia (VT) due to dilated cardiomyopathy (DCM) is difficult to treat, and long-term outcome data are limited. ObjectivesThe aim of this study was to identify predictors of mortality or heart transplantation (HTx) and VT recurrence. MethodsConsecutive patients with DCM accepted for radiofrequency catheter ablation (RFCA) of VT at 9 centers were prospectively enrolled and followed. ResultsOf 281 consecutive patients (mean age 60 ± 13 years, 85% men, mean left ventricular ejection fraction [LVEF] 36% ± 12%), 35% had VT storm, 20% had incessant VT, and amiodarone was unsuccessful in 68%. During follow-up of 21 months (IQR: 6-30 months), 67 patients (24%) died or underwent HTx, and 138 (49%) had VT recurrence (45 within 30 days, defined as early); the 4-year rate of VT recurrence or mortality or HTx was 70%. Independent predictors of mortality or HTx were early VT recurrence (HR: 2.92; 95% CI: 1.37-6.21; P < 0.01), amiodarone at discharge (HR: 3.23; 95% CI: 1.43-7.33; P < 0.01), renal dysfunction (HR: 1.92; 95% CI: 1.01-3.64; P = 0.046), and LVEF (HR: 1.36; 95% CI: 1.0-1.84; P = 0.052). LVEF ≤32% identified patients at risk for mortality or HTx (area under the curve: 0.75). Mortality or HTx per 100 person-years was 40.4 events after early, compared with 14.2 events after later VT recurrence and 8.5 events with no VT recurrence after RFCA (P < 0.01 for both). Patients with early recurrence and LVEFs ≤32% had a 1-year rate of mortality or HTx of 55%. VT recurrence was predicted by prior implantable cardioverter-defibrillator shocks, basal anteroseptal VT origin, and procedural failure but not LVEF. ConclusionsPatients with DCM needing RFCA for VT are a high-risk group. Following RFCA, approximately one-half remain free of VT recurrence. Early VT recurrence with LVEF ≤32% identifies those at very high risk for mortality or HTx, and screening for mechanical support or HTx should be considered. Late VT recurrence after RFCA does not predict worse outcome.

Radiofrequency catheter ablation of ventricular tachycardia in ischemic heart disease in light of current practice: a systematic review and meta-analysis of randomized controlled trials.

Ventricular tachycardia (VT) is a frequent cause of mortality and morbidity in patients with ischemic heart disease (IHD). We aim to perform a systematic review and meta-analysis of randomized controlled trials (RCT) of radiofrequency catheter ablation (RCA) of VT in patients with IHD and to discuss its appropriate timing and limitations. Literature searches of MEDLINE, CENTRAL, the Cochrane Database of Systematic Reviews, Health Technology Assessment, and PsycINFO were performed in February 2020. RCTs comparing RCA vs conventional management for VT in patients with IHD and previous or planned implantable cardioverter defibrillator (ICD) were identified. Clinical outcomes included all-cause mortality, cardiovascular mortality, cardiovascular hospitalization, VT storm, recurrent VT/ventricular fibrillation (VF), appropriate ICD therapies, and appropriate ICD shocks. Using a random-effects model, relative risk (RR) and 95% confidence intervals (CI) were calculated for each outcome. A total of 6 RCTs (N= 791) met inclusion criteria. RCA was associated with significantly lower VT storm (RR 0.70; CI95% 0.51 to 0.94, p= 0.02) and appropriate ICD therapies (RR 0.69; CI95% 0.54 to 0.88, p= 0.003), including appropriate ICD shocks (RR 0.66; CI95% 0.47 to 0.92, p= 0.02). There was no significant difference in all-cause or cardiovascular mortality, cardiovascular hospitalization, and recurrent VT/VF. Radiofrequency catheter ablation for VT in patients with IHD was associated with a reduced risk of VT storm, ICD therapies, and ICD shocks. There is a need for future carefully designed RCTs that incorporate improved RCA procedural aspects.

Ablation of Ventricular Tachycardia in Congenital and Infiltrative Heart Disease.

Radiofrequency catheter ablation (RFCA) is an important treatment modality to prevent ventricular tachycardia (VT) recurrence in patients with repaired congenital heart disease. Identification and ablation of anatomic isthmuses has improved acute ablation outcome with excellent VT-free survival in those with preserved biventricular function. Reports on RFCA for VT in patients with infiltrative disease are sparse and cardiac sarcoidosis seems to be the most prevalent cause for ventricular arrhythmia. Patients with active and ongoing inflammation are at high risk for VT recurrence. RFCA reduces the number of VT but often multiple procedures are required and long-term VT-free survival is unfavorable in those with left ventricular dysfunction.

Should all patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy undergo epicardial catheter ablation?

Epicardial radiofrequency catheter ablation is currently considered as the therapeutic option of choice in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) and recurrent ventricular tachycardia (VT). We hypothesised that inducibility of VT may guide the ablation strategy and thereby affect long-term results. Additional epicardial ablation was only performed if VT were still inducible after thorough endocardial ablation. The objective was to examine an inducibility-guided ablation approach by comparing the long-term results between endocardial and epi-endocardial radiofrequency catheter ablation of VT in a large cohort of patients with ARVD/C. We studied from our ARVD/C registry (70 patients in total, 48 males, age 53.2 ± 14.0) 45 patients (64.3% of all patients) who underwent catheter ablation of VT. All patients received endocardial VT ablation. After endocardial ablation, 24 patients (53.3%) remained inducible. Additional epicardial ablation was performed in 22 patients (48.9%). After ablation, non-inducibility was achieved in overall 38 patients (84.4%). During a mean follow-up of 31.1 ± 27.4months, 13 patients in each group (59.1% after endo- and epicardial ablation, 56.5% after endocardial ablation) remained free from VT recurrence (P = 0.862). An inducibility-guided catheter ablation strategy of VT in patients with ARVD/C prevents unnecessary epicardial ablation and may therefore be considered as an alternative to primary combined endo- and epicardial ablation.

16-35: Catheter Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Cardiomyopathy – Experience of a Tertiary Care Center

Introduction: Sustained Ventricular Tachycardia (VT) is common in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC/D), and associated with frequent ICD interventions, hospitalizations, and reduced quality of life. Antiarrhythmic drugs are not always effective in suppressing ventricular arrhythmias in this cardiomyopathy, and frequently associated with side effects. Aim: We assessed short-term outcomes of radiofrequency catheter ablation (RFA) for VT in a single-center cohort of patients with ARVC/D. Methods: All RFA procedures addressing VT performed in our tertiary-care center between 1998 and 2015 in 40 patients (49.2 ± 15.8 years of age; 83% male) with definite (n = 32) or borderline (n = 8) ARVC/D were analyzed. Procedural data and short-term success were determined. Results: 71 RFA procedures using a three-dimensional mapping system were performed (mean 1.8 per patient), of these 55% (n = 39) using an endocardial approach, 34% (n = 24) using a combined endo-epicardial approach, and 11% (n = 8) using an epicardial approach. VT was inducible in 86% of patients referred for RFA of VT. In 44% of ablations, >1 sustained VT was inducible, and multiple VT morphologies (mean 1.5 ± 1.0) were common (38%). The mean cycle length of induced VT was 351 ± 78ms. Most VT had a LBBB morphology and superior axis, correlating with the subtricuspid area as the most frequent VT exit site. Although fibro-fatty infiltration typically begins subepicardially, an endocardial substrate with low voltage (bipolar <1.5 mV) and fragmented/late potentials was found in the majority of patients (55%). Procedural data are shown in the table. RFA was successful (defined as abolishment of all inducible sustained VTs) in 86%, and partially successful (defined as abolishment of all clinical VTs) in 10%. 3 procedures on two different patients were not successful. The reason was the close proximity of the target substrate and ICD lead (combined endo-/epicardial approach) in the first case, and hemodynamically not tolerable VT in the second patient. VT ablation was generally safe with 1 (1.4%) pericardial tamponade occurring after epicardial puncture, and 9 minor complications (pericardial effusion n = 2, mild pericarditis n = 4, mild femoral hematoma n = 3). The majority of patients had an ICD (76%). The number of sustained VT significantly decreased after RFA compared to before RFA (27 ± 38 vs. 4 ± 12, p < 0.05). The percentage of patients on antiarrhythmic drugs did not significantly change before and after RFA (93% vs. 90%, p = ns). Conclusions: RFA is an effective strategy to reduce the sustained VT burden in patients with ARVC/D. Although the pathologic process begins in the subepicardium, the majority of patients referred for VT ablation has rather advanced disease stages, and thus presents with an endocardial substrate amenable to endocardial RFA. Endocardial RFA has a high acute success rate, potentially obviating the need for a more invasive epicardial approach in some of these patients.

Outcomes and ventricular tachycardia recurrence characteristics after epicardial ablation of ventricular tachycardia in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Variable success rates have been reported after epicardial radiofrequency catheter ablation (RFA) in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The details of the electroanatomic substrate are limited to a few studies, and the characteristics of the recurrent ventricular tachycardia (VT) in ARVD/C remain largely unknown. The purpose of this study was to report procedural strategy, safety, and efficacy of epicardial RFA at a tertiary single center with a focus on the characteristics of the substrate and recurrent VT. We included 30 ARVD/C patients (mean age 33.1 ± 11.1 years, 53% male) who underwent endocardial/epicardial mapping and epicardial catheter ablation of VT at the Johns Hopkins Hospital. Implantable cardioverter-defibrillator interrogations were evaluated for VT recurrence. The majority of critical VT circuits (69%) were on the epicardial surface, mostly in the subtricuspid region. Eight patients (27%) experienced VT recurrence after epicardial RFA, and the VT-free survival was 83%, 76%, and 70% at 6,12, and 24, months respectively. A significant reduction of VT burden was observed (P <.001), even among those with VT recurrence. No complications occurred except for acute pericarditis in 1 patient. The majority of VT recurrences occurred during the first year after RFA, during exercise, had fast cycle lengths, and required implantable cardioverter-defibrillator shock for termination. The vast majority of critical VT circuits were epicardial, mostly in the subtricuspid region. Epicardial RFA of VT appears to be both safe and effective in achieving arrhythmia control in ARVD/C. The features of the recurrent VT suggest a possible catecholamine-mediated mechanism with an origin in a region not targeted for ablation.

Re-entry using anatomically determined isthmuses: a curable ventricular tachycardia in repaired congenital heart disease.

Ventricular tachycardia (VT) is an important cause of late morbidity and mortality in repaired congenital heart disease. The substrate often includes anatomic isthmuses that can be transected by radiofrequency catheter ablation similar to isthmus block for atrial flutter. This study evaluates the long-term efficacy of isthmus block for treatment of re-entry VT in adults with repaired congenital heart disease. Thirty-four patients (49±13 years; 74% male) with repaired congenital heart disease who underwent radiofrequency catheter ablation of VT in 2 centers were included. Twenty-two (65%) had a preserved left and right ventricular function. Patients were inducible for 1 (interquartile range, 1-2) VT, median cycle length: 295 ms (interquartile range, 242-346). Ablation aimed to transect anatomic isthmuses containing VT re-entry circuit isthmuses. Procedural success was defined as noninducibility of any VT and transection of the anatomic isthmus and was achieved in 25 (74%) patients. During long-term follow-up (46±29 months), all patients with procedural success (18/25 with internal cardiac defibrillators) were free of VT recurrence but 7 of 18 experienced internal cardiac defibrillator-related complications. One patient with procedural success and depressed cardiac function received an internal cardiac defibrillator shock for ventricular fibrillation. None of the 18 patients (12/18 with internal cardiac defibrillators) with complete success and preserved cardiac function experienced any ventricular arrhythmia. In contrast, VT recurred in 4 of 9 patients without procedural success. Four patients died from nonarrhythmic causes. In patients with repaired congenital heart disease with preserved ventricular function and isthmus-dependent re-entry, VT isthmus ablation can be curative.

Precordial QRS amplitude ratio predicts long-term outcome after catheter ablation of electrical storm due to ventricular tachycardias in patients with arrhythmogenic right ventricular cardiomyopathy

BackgroundRadiofrequency catheter ablation is currently considered as the therapeutic option of choice in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and recurrent ventricular tachycardia (VT). MethodsThis study intended to assess the long-term outcome of catheter ablation in patients with ARVC and electrical storm. The specific objective was to assess the relationship between precordial QRS amplitude ratio and outcome of catheter ablation in these patients. ResultsTwenty-eight patients (19 men, age 52.3±14.2years) underwent 48 catheter ablation procedures (range 1–6, six epicardial). During a mean follow-up of 18.7±15.1months, 13 patients (46.5%) experienced VT recurrence. Age >50years and ∑QRSmvV1–V3/∑QRSmvV1–V6≤0.48 but not right ventricular size and acute ablation outcome were associated with VT recurrence during the follow up. ConclusionAge >50years and ∑QRSmvV1–V3/∑QRSmvV1–V6≤0.48 predict recurrence of VT after successful radiofrequency catheter ablation of VT in patients with ARVC and electrical storm.

Outcomes in Catheter Ablation of Ventricular Tachycardia in Dilated Nonischemic Cardiomyopathy Compared With Ischemic Cardiomyopathy

Data on the outcomes of ventricular tachycardia (VT) ablation in nonischemic dilated cardiomyopathy (NIDCM) are insufficient. The Heart Center of Leipzig VT (HELP-VT) study was conducted prospectively to compare outcomes after radiofrequency catheter ablation of VT in patients with NIDCM compared with ischemic cardiomyopathy (ICM). Two hundred twenty-seven patients, 63 with NIDCM and 164 with ICM, presenting with sustained VT were ablated with radiofrequency catheter ablation. Noninducibility of any clinical and nonclinical VT was achieved in 66.7% of NIDCM and in 77.4% of ICM patients. Ablation of the clinical VT only was achieved in 18.3% of ICM and in 22.2% of NIDCM patients. There was no statistically significant difference in short-term outcomes between the 2 groups. At the 1-year follow-up, VT-free survival in NIDCM was 40.5% compared with 57% in ICM. In univariate analysis, the hazard ratio for VT recurrence was significantly higher for NIDCM (1.62; 95% confidence interval, 1.12- 2.34; P=0.01). In both the ICM and NIDCM subgroups, procedure failure and incomplete procedural success were independent predictors of VT recurrence. Although the short-term success rates after VT ablation in NIDCM and ICM patients were similar, the long-term outcomes in NIDCM patients were significantly worse. Complete VT noninducibility at the end of the ablation is associated with beneficial long-term outcome in NIDCM. Pursuing compete elimination of all inducible VTs is desirable and may improve the long-term success in NIDCM.

Determinants of Postinfarction Ventricular Tachycardia

Structural factors contributing to the development of postinfarction ventricular tachycardia (VT) are unclear. The purpose of this study was to analyze infarct architecture and electrogram characteristics in patients with and without inducible VT and to identify correlates of postinfarction VT. Twenty-four postinfarction patients (median age, 64 [53, 70] years) were referred for radiofrequency catheter ablation of VT (n = 12) or frequent symptomatic premature ventricular contractions (PVCs) (n = 12). Delayed-enhanced (DE) MRI was obtained before ablation. Electroanatomical mapping was performed and scar area and electrogram characteristics of the scar tissue compared in patients with and without inducible VT. The median ejection fraction in patients with and without inducible VT was 27% (22%, 43%) and 43% (40%, 47%), respectively (P = 0.085). Subendocardial infarct area determined by DE-MRI was larger in patients with inducible VT (43 [38, 62] cm(2)) than in those with noninducible VT (8 [4, 11] cm(2); P = 0.002), and unipolar and bipolar voltages on electroanatomical maps were significantly lower in patients with inducible VT (both P<0.05). An infarct volume of >14% identified 11 of 12 patients with inducible VT (area under the curve, 0.94; P = 0.007). On electroanatomical mapping, distinct sites with isolated potentials (IPs) were more prevalent in patients with inducible VT than in those without (13.2% versus 1.1% of points within scar; P < 0.001). The number of inducible VTs correlated with the number of distinct sites with IPs (R = 0.87; P<0.0001). Scar tissue in postinfarction patients with inducible VT shows quantitative and qualitative differences from scars in patients without inducible VT. Scar size and IPs are correlated with VT inducibility.

Long-Term Efficacy of Catheter Ablation of Ventricular Tachycardia in Patients With Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

This study sought to evaluate the outcomes of radiofrequency catheter ablation (RFA) of ventricular tachycardia (VT) in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) patients. Particular focus was placed on defining the single-procedure efficacy over long-term follow-up. ARVD/C is an inherited cardiomyopathy characterized by VT and right ventricular dysfunction. Prior single-center studies have reported conflicting results concerning the efficacy of RFA of VT in ARVD/C patients. The study population comprised 24 patients (age 36 +/- 9 years, 11 male), enrolled in the Johns Hopkins ARVD registry, who underwent 1 or more RFA procedures for treatment of VT. Patients were followed up for 32 +/- 36 months (range 1 day to 12 years). Recurrence was defined as the documentation of VT subsequent to the procedure. A total of 48 RFA procedures were performed using 3-dimensional electroanatomical (n = 10) or conventional (n = 38) mapping. Of these procedures, 22 (46%), 15 (31%), and 11 (23%) resulted in elimination of all inducible VTs, clinical VT but not all, and none of the inducible VTs, respectively. Forty (85%) procedures were followed by recurrence. The cumulative VT recurrence-free survival was 75%, 50%, and 25% after 1.5, 5, and 14 months, respectively. The cumulative VT recurrence-free survival did not differ by procedural success, mapping technique, or repetition of procedures. There was 1 procedure-related death. Our study shows a high rate of recurrence in ARVD/C patients undergoing RFA of VT. This likely reflects the fact that ARVD/C is a diffuse cardiomyopathy with progressively evolving electrical substrate. Further studies are needed to define the precise role of RFA of VT in ARVD/C.

Ventricular tachycardia in nonpostoperative pediatric patients: role of radiofrequency catheter ablation.

Experience concerning radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in pediatric patients is limited. In adults, success rates vary widely based on the etiology of the VT. Highest success rates have been achieved in patients without structural heart disease. Between March 1998 and December 1999, five young patients (age, 5 months to 15 years; body weight, 5.5-61.6 kg) underwent RFCA for VT at our institution [structurally normal heart (n = 4), preoperative tetralogy of Fallot (n = 1)]. Monomorphic VT was present in four children, and an infant with MIDAS syndrome had polymorphic VT. Clinical presentation varied: palpitations, n = 2, congestive heart failure, n = 3. All patients had been proven to be unresponsive to one to six (median, three) antiarrhythmic drugs. In all five patients, VT could be successfully eliminated by RFCA after a total of nine (range, 1-4) procedures. Activation mapping and pace mapping were used to identify the anatomical substrate, which was located in the right ventricle/right ventricular outflow tract in all four patients with monomorphic VT and in the left ventricular septum/left ventricular free wall in the infant with polymorphic VT. There were no significant complications in any patient. During follow-up (20-42 months), all patients are in normal sinus rhythm. Left ventricular function recovered in all three patients who had initially presented with congestive heart failure. RFCA can be effective, safe, and life saving in children with medically resistant VT who have not been operated on for congenital heart disease, even when the VT is polymorphic. Although the number of patients is small, RFCA may be the treatment of choice for symptomatic VT in pediatric patients.