This thesis aims to improve the understanding and identification of the ventricular tachycardia substrate in patients with right ventricular tachycardia. An isolated epicardial right ventricular... Show moreThis thesis aims to improve the understanding and identification of the ventricular tachycardia substrate in patients with right ventricular tachycardia. An isolated epicardial right ventricular outflow tract scar is described in high level endurance athletes. Novel parameters such as endocardial unipolar voltage, transmural activation time and CT heterogeneity may help to guide substrate mapping and ablation. Implementing these techniques in current clinical practice may improve the identification and treatment of ventricular tachycardia substrates in right ventricular cardiomyopathies. Show less
Aims In right ventricular cardiomyopathy (RVCM), intramural scar may prevent rapid transmural activation, which may facilitate subepicardial ventricular tachycardia (VT) circuits. A critical... Show moreAims In right ventricular cardiomyopathy (RVCM), intramural scar may prevent rapid transmural activation, which may facilitate subepicardial ventricular tachycardia (VT) circuits. A critical transmural activation delay determined during sinus rhythm (SR) may identify VT substrates in RVCM. Methods and results Consecutive patients with RVCM who underwent detailed endocardial-epicardial mapping and ablation for scar-related VT were enrolled. The transmural activation interval (TAI, first endocardial to first epicardial activation) and maximal activation interval (MAI, first endocardial to last epicardial activation) were determined in endocardial-epicardial point pairs located <10 mm apart. VT-related sites were determined by conventional substrate mapping and limited activation mapping when possible. Nineteen patients (46 +/- 16 years, 84% male, 63% arrhythmogenic right ventricular cardiomyopathy, 37% exercise-induced arrhythmogenic remodelling) were inducible for 44 VT [CL 283 (interquartile range, IQR 240-325)ms]. A total of 2569 endocardial-epicardial coupled point pairs were analysed, including 98 (4%) epicardial VT-related sites. The TAI and MAI were significantly longer at VT-related sites compared with other electroanatomical scar sites [TAI median 31 (IQR 11-50) vs. 2 (-7-11)ms, P < 0.001; MAI median 65 (IQR 45-87) vs. 23 (13-39)ms, P < 0.001]. TAI and MAI allowed highly accurate identification of epicardial VT-related sites (optimal cut-off TAI 17 ms and MAI 45 ms, both AUC 0.81). Both TAI and MAI had a better predictive accuracy for VT-related sites than endocardial and epicardial voltage and electrogram (EGM) duration (AUC 0.51-0.73). Conclusion The transmural activation delay in SR can be used to identify VT substrates in patients with RVCM and predominantly hemodynamically non-tolerated VT, and may be an important new mapping tool for substrate-based ablation. Show less
Aims: Arrhythmogenic right ventricular cardiomyopathy (ARVC) patients have an increased risk of ventricular arrhythmias (VA). Four implantable cardioverter-defibrillator (ICD) recommendation... Show moreAims: Arrhythmogenic right ventricular cardiomyopathy (ARVC) patients have an increased risk of ventricular arrhythmias (VA). Four implantable cardioverter-defibrillator (ICD) recommendation algorithms are available The International Task Force Consensus ('ITFC'), an ITFC modification by Orgeron et al. ('mITFC'), the AHA/HRS/ACC guideline for VA management ('AHA'), and the HRS expert consensus statement ('HRS'). This study aims to validate and compare the performance of these algorithms in ARVC. Methods and results: We classified 617 definite ARVC patients (38.5 +/- 15.1 years, 52.4% male, 39.2% prior sustained VA) according to four algorithms. Clinical performance was evaluated by sensitivity, specificity, ROC-analysis, and decision curve analysis for any sustained VA and for fast VA (>250 b.p.m.). During 6.4 [2.8-11.5] years follow-up, 282 (45.7%) patients experienced any sustained VA, and 63 (10.2%) fast VA. For any sustained VA, ITFC and mITFC provide higher sensitivity than AHA and HRS (94.0-97.8% vs. 76.7-83.5%), but lower specificity (15.9-32.0% vs. 42.7%-60.1%). Similarly, for fast VA, ITFC and mITFC provide higher sensitivity than AHA and HRS (95.2-97.1% vs. 76.7-78.4%) but lower specificity (42.7-43.1 vs. 76.7-78.4%). Decision curve analysis showed ITFC and mITFC to be superior for a 5-year sustained VA risk ICD indication threshold between 5-25% or 2-9% for fast VA. Conclusion: The ITFC and mITFC provide the highest protection rates, whereas AHA and HRS decrease unnecessary ICD placements. ITFC or mITFC should be used if we consider the 5-year threshold for ICD indication to lie within 5-25% for sustained VA or 2-9% for fast VA. These data will inform decision-making for ICD placement in ARVC. Show less
Hoogendoorn, J.C.; Venlet, J.; Out, Y.N.J.; Man, S.; Kumar, S.; Sramko, M.; ... ; Zeppenfeld, K. 2021
BACKGROUND Cardiac sarcoidosis (CS) with right ventricular (RV) involvement can mimic arrhythmogenic right ventricular cardiomyopathy (ARVC). Histopathological differences may result in disease... Show moreBACKGROUND Cardiac sarcoidosis (CS) with right ventricular (RV) involvement can mimic arrhythmogenic right ventricular cardiomyopathy (ARVC). Histopathological differences may result in disease-specific RV activation patterns detectable on the 12-lead electrocardiogram. Dominant subepicardial scar in ARVC leads to delayed activation of areas with reduced voltages, translating into terminal activation delay and occasionally (epsilon) waves with a small amplitude. Conversely, patchy transmural RV scar in CS may lead to conduction block and therefore late activated areas with preserved voltages reflected as preserved R' waves.OBJECTIVE The purpose of this study was to evaluate the distinct terminal activation patterns in precordial leads V-1 through V-3 as a discriminator between CS and ARVC.METHODS Thirteen patients with CS affecting the RV and 23 patients with gene-positive ARVC referred for ventricular tachycardia ablation were retrospectively included in a multicenter approach. A non-ventricular-paced 12-lead surface electrocardiogram was analyzed for the presence and the surface area of the R' wave (any positive deflection from baseline after an S wave) in leads V-1 through V-3.RESULTS An R' wave in leads V-1 through V-3 was present in all patients with CS compared to 11 (48%) patients with ARVC (P=.002). An algorithm including a PR interval of >= 220 ms, the presence of an R' wave, and the surface area of the maximum R' wave in leads V-1 through V-3 of similar to 1.65 mm(2) had 85% sensitivity and 96% specificity for diagnosing CS, validated in a second cohort (18 CS and 40 ARVC) with 83% sensitivity and 88% specificity.CONCLUSION An easily applicable algorithm including PR prolongation and the surface area of the maximum R' wave in leads V-1 through V-3 of similar to 1.65 mm(2) distinguishes CS from ARVC. This QRS terminal activation in precordial leads V-1 through V-3 may reflect disease-specific scar patterns. Show less
Aims Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by ventricular arrhythmias (VAs) and sudden cardiac death (SCD). We aimed to develop a model for... Show moreAims Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by ventricular arrhythmias (VAs) and sudden cardiac death (SCD). We aimed to develop a model for individualized prediction of incident VA/SCD in ARVC patients.Methods and results Five hundred and twenty-eight patients with a definite diagnosis and no history of sustained VAs/SCD at baseline, aged 38.2 +/- 15.5 years, 44.7% male, were enrolled from five registries in North America and Europe. Over 4.83 (interquartile range 2.44-9.33) years of follow-up, 146 (27.7%) experienced sustained VA, defined as SCD, aborted SCD, sustained ventricular tachycardia, or appropriate implantable cardioverter-defibrillator (ICD) therapy. A prediction model estimating annual VA risk was developed using Cox regression with internal validation. Eight potential predictors were pre-specified: age, sex, cardiac syncope in the prior 6 months, non-sustained ventricular tachycardia, number of premature ventricular complexes in 24 h, number of leads with T-wave inversion, and right and left ventricular ejection fractions (LVEFs). All except LVEF were retained in the final model. The model accurately distinguished patients with and without events, with an optimism-corrected C-index of 0.77 [95% confidence interval (CI) 0.73-0.81] and minimal over-optimism [calibration slope of 0.93 (95% CI 0.92-0.95)]. By decision curve analysis, the clinical benefit of the model was superior to a current consensus-based ICD placement algorithm with a 20.6% reduction of ICD placements with the same proportion of protected patients (P < 0.001).Conclusion Using the largest cohort of patients with ARVC and no prior VA, a prediction model using readily available clinical parameters was devised to estimate VA risk and guide decisions regarding primary prevention ICDs (www.arvcrisk.com). Show less
BACKGROUND The comparative efficacy of antiarrhythmic drug (AAD) therapy vs ventricular tachycardia (VT) ablation in arrhythmogenic right ventricular cardiomyopathy (ARVC) is unknown.OBJECTIVE We... Show moreBACKGROUND The comparative efficacy of antiarrhythmic drug (AAD) therapy vs ventricular tachycardia (VT) ablation in arrhythmogenic right ventricular cardiomyopathy (ARVC) is unknown.OBJECTIVE We compared outcomes of AAD and/or beta-blocker (BB) therapy with those of VT ablation (with AAD/BB) in patients with ARVC who had recurrent VT.METHODS In a multicenter retrospective study, 110 patients with ARVC (mean age 38 +/- 17 years; 91[83%] men) with a minimum of 3 VT episodes were included; 77 (70%) were initially treated with AAD/BB and 32 (29%) underwent ablation. Subsequently, 43 of the 77 patients treated with AAD/BB alone also underwent ablation. Overall, 75 patients underwent ablation.RESULTS When comparing initial AAD/BB therapy (n = 77) and VT ablation (n = 32) after >= 3 VT episodes, a single ablation procedure rendered 35% of patients free of VT at 3 years compared with 28% of AAD/BB-only-treated patients (P =.46). Of the 77 AAD/BB-only-treated patients, 43 subsequently underwent ablation. For all 75 patients who underwent ablation, 56% were VT-free at 3 years after the last ablation procedure. Epicardial ablation was used in 40/75 (53%) and was associated with lower VT recurrence after the last ablation procedure (endocardial/epicardial vs endocardial-only; 71% vs 47% 3-year VT-free survival; P =.05). Importantly, there was no difference in survival free of death or transplantation between the ablation- and AAD/BB-only-treated patients (P =.61).CONCLUSION In patients with ARVC and a high VT burden, mortality and transplantation-free survival are not significantly different between drug- and ablation-treated patients. These patients have a high risk of recurrent VT despite drug therapy. Combined endocardial/epicardial ablation is associated with reduced VT recurrence as compared with endocardial-only ablation. Show less
