INTRODUCTION AND OBJECTIVES: We sought to demonstrate the mode of spontaneous onset of sustained monomorphic ventricular tachycardia in patients with Chagas' cardiomyopathy. METHODS: We studied 222 stored electrograms in 14 patients with Chagas cardiomyopathy and spontaneous monomorphic ventricular tachycardia treated with a cardioverter defibrillator. Premature ventricular complexes before ventricular tachycardia were classified by morphology and number. The onset was considered "sudden" if no previous premature ventricular complexes were present, and "extrasystolic" if a ventricular extrasystole precedeed SMVT initiation. Prematurity was evaluated by the coupling interval and a calculated prematurity ratio (RR'/RR). RESULTS: Two-hundred and nine episodes (94%) were initiated by late-coupled premature ventricular complexes (prematurity ratio >0.5). The mean coupling interval of the initiating beat was 565+/-117 ms with a mean prematurity ratio of 0.72+/-0.15. A sudden onset was the most frequent pattern of ventricular tachycardia initiation (129 episodes, 58%). Among the extrasystolic onset (93 episodes, 42%), 48 were due to multiple premature ventricular complexes and 88 had a different QRS complex (electrogram) morphology of the ventricular extrasystoles than that recorded during the subsequent ventricular tachycardia. The arrhythmia was preceded by a short-long-short sequence in 95/222 episodes (43%). CONCLUSIONS: In implantable cardioverter defibrillator recipients with Chagas cardiomyopathy, spontaneous monomorphic ventricular tachycardia episodes are typically initiated by late-coupled premature ventricular complexes, which often show a short-long-short sequence.
INTRODUCTION AND OBJECTIVES: We sought to demonstrate the mode of spontaneous onset of sustained monomorphic ventricular tachycardia in patients with Chagas' cardiomyopathy. METHODS: We studied 222 stored electrograms in 14 patients with Chagas cardiomyopathy and spontaneous monomorphic ventricular tachycardia treated with a cardioverter defibrillator. Premature ventricular complexes before ventricular tachycardia were classified by morphology and number. The onset was considered "sudden" if no previous premature ventricular complexes were present, and "extrasystolic" if a ventricular extrasystole precedeed SMVT initiation. Prematurity was evaluated by the coupling interval and a calculated prematurity ratio (RR'/RR). RESULTS: Two-hundred and nine episodes (94%) were initiated by late-coupled premature ventricular complexes (prematurity ratio >0.5). The mean coupling interval of the initiating beat was 565+/-117 ms with a mean prematurity ratio of 0.72+/-0.15. A sudden onset was the most frequent pattern of ventricular tachycardia initiation (129 episodes, 58%). Among the extrasystolic onset (93 episodes, 42%), 48 were due to multiple premature ventricular complexes and 88 had a different QRS complex (electrogram) morphology of the ventricular extrasystoles than that recorded during the subsequent ventricular tachycardia. The arrhythmia was preceded by a short-long-short sequence in 95/222 episodes (43%). CONCLUSIONS: In implantable cardioverter defibrillator recipients with Chagas cardiomyopathy, spontaneous monomorphic ventricular tachycardia episodes are typically initiated by late-coupled premature ventricular complexes, which often show a short-long-short sequence.
Authors: Ameeta Yaksh; Charles Kik; Paul Knops; Korinne Zwiers; Maarten J B van Ettinger; Olivier C Manintveld; Marcel C J de Wijs; Peter van der Kemp; Ad J J C Bogers; Natasja M S de Groot Journal: J Cardiothorac Surg Date: 2016-07-08 Impact factor: 1.637