[Electrophysiological changes of the excitoconduction system in patients with Chagas cardiomyopathy and their modification by flecainide].

We studied 20 patients with a confirmed diagnosis of Chagas heart disease. Clinical and electrocardiography examinations at baseline documented that all patients had chronic PVC's and that 40% of them also had supraventricular extrasystoles. Also 80% of the patients had RBBB's, 70% had LBBB's and 35% had 1st. degree AV blocks. Flecainide (F) completely suppressed the arrhythmias in 85% of the patients and did partially so in 98% of the patients. Flecainide did not affect sinus node function except in one patient who developed a sinus node atrial block. PR and QRS intervals were prolonged after F but there no 2nd or 3rd degree AV blocks. Flecainide demonstrated to be highly effective with a comfortable margin of safety in the management of these patients with marked alterations of their pace-making and conduction functions.