Modo de inicio de las taquiarritmias ventriculares en la cardiopatía chagásica crónica / Initiation mode of ventricular tachyarrhythmias in chronic Chagas' cardiomyopathy

ABSTRACT

AIM: The purpose of this study was to investigate the modes of initiation of malignant ventricular tachyarrhythmias in patients with Chagas' cardiomyopathy (ChC) with an implantable cardioverter-defibrillator (ICD) through the analysis of stored intracardiac electrograms. Specifically, we analyzed the incidence of ventricular arrhythmias preceded by the short-long-short-pattern (sls). METHODS: We analyzed 179 spontaneous malignant ventricular tachyarrhythmias episodes in 15 patients with Chagas' cardiomyopathy with an ICD. The mean cycle length in normal sinus rhythm before initiation of the malignant ventricular tachyarrhythmias, the ventricular tachycardia (VT) cycle length, the prematurity ratio and the number of ventricular premature contractions (VPCs) (single, pairs or multiple) that triggered malignant ventricular tachyarrhythmias were compared between the two different initiation modes. RESULTS: Mean age 60.4 +/- 5.7 -years-old, mean EF, 33.2 +/- 8.5%, 9 men and 6 women. A sls-pattern was found in 43.5% of the malignant ventricular tachyarrhythmias. Baseline cycle length (795 +/- 16 vs 788 +/- 14 ms), VT cycle length (320 +/- 7.7 ms vs 329 +/- 5.7 ms) and prematurity ratio (0.57 +/- 11 vs 0.60 +/- 12) were similar between sls and non-sls-sequences. Multiple VPCs as a trigger of malignant ventricular tachyarrhythmias was significantly less often in sls-events than in non-sls events (14% vs 40%; P < 0.0001). CONCLUSIONS: In this select population of patients with ChC, we observed a high prevalence of sls-pattern just before initiation of malignant ventricular tachyarrhythmias. Multiple VPCs were often associated with a non-sls trigger mode.