This prospective study was designed to evaluate intraventricular conduction disturbances in asymptomatic patients with Chagas' disease, and patients with primary sclerosis of the conducting system of the heart (Lev-Lenègre's disease). Eighty-four asymptomatic individuals with right- or left-bundle branch block were submitted to electrophysiological evaluation and long-term follow-up. Fifty-five had positive serologic blood tests for Chagas' disease and 29 had Lev-Lenègre's disease. Mean-age of 45 years in chagasic and 63 in non-chagasic patients (p< 0.001). There were 54 (98.2%) with right-bundle branch block in chagasic and 14 (48.3%) among non-chagasic patients (p <0.001). Sinus nodal and atrioventricular nodal functions presented no differences in either group. However, mean HV interval was greater in the NCH than in the CH group (p< 0.01). After a mean follow-up of 121 ± 63.75 months among chagasic and 94.97 ± 67.55 months among non-chagasic patients, total mortality was 20 (36.6%) patients in chagasic and 9 (31%) among non-chagasic patients (NS). Cardiac death was recorded in 17 (85%) individuals among chagasic and 3 (33.3%) among non-chagasic patients(p <0.05). Sudden death occurred in 10 (50%) among chagasic and was not observed in non-chagasic patients (p <0.01). In conclusion: 1. Asymptomatic chagasic individuals with intraventricular conduction disturbances showed higher cardiac mortality, sudden or non-sudden death in relation to non-chagasic individuals. 2. The evaluated electrophysiological parameters were of no prognostic value in relation to mortality, although programmed ventricular stimulation was not performed.
Chagas' disease; Intraventricular conduction disturbances; Sudden death
