Electrocardiographic abnormalities and left ventricular systolic function in Chagas' heart disease.

In chagasic patients, the electrocardiogram becomes abnormal very late in the course of the disease. Most clinical studies concerning cardiac autonomic function of chagasic patients have been carried out in this very late stage of the disease. The purpose of this study was to assess accurately the left ventricular systolic function of chagasic patients with abnormal electrocardiograms. We performed left ventricular contrast cineangiography in 44 patients with positive complement fixation test for Chagas' disease and abnormal electrocardiograms. On the basis of the electrocardiographic abnormalities found in the electrocardiogram taken the night before the hemodynamic procedure, we divided our patients into three subgroups; those with rhythm disturbances, those with ventricular conduction abnormalities, and those with rhythm disturbances plus ventricular conduction abnormalities. The chagasic patients with only cardiac rhythm disturbances, had left ventricular volumes and ejection fractions which were similar to those of controls. On the other hand, the left ventricular volumes of the chagasic patients with ventricular conduction defects, although slightly larger, were still not different from those of controls. Finally, the chagasic patients, with cardiac rhythm disturbances and left ventricular conduction defects, had the largest left ventricular volumes (P less than 0.05), and the lowest ejection fractions (P less than 0.001) of all three subgroups. These findings clearly indicate that chagasic patients, in this very late stage of the disease, have a very variable degree of left ventricular systolic dysfunction. Furthermore, our results show a distinct tendency for the left ventricular volumes to increase, and for the ejection fraction to decrease; when the electrocardiogram becomes progressively more abnormal, and "mixed" electrocardiographic abnormalities appear.(ABSTRACT TRUNCATED AT 250 WORDS)

[The anti-arrhythmia effect of carbamazepine in chagasic patients with advanced myocardial damage]. / Effecto antiarrítmico de la carbamazepina en pacientes chagásicos con daño miocárdico avanzado.

Oral administration of 600 mg/day of carbamazepine to 14 arrhythmic chagasic patients with advanced myocardial damage and no signs of congestive heart failure did not alter the frequency of ventricular extrasystoles, but reduced the total number of supraventricular ectopic beats in 7/14 patients and the episodes of complex ventricular arrhythmias in up to 43% of patients. This assessment was made from 24 hour continuous Holter recording during the course of this double-blind, placebo controlled, randomized crossover study. Serum levels of carbamazepine were also determined and found within therapeutic limits. Six patients complained of minor side effects. One patient presented with iatrogenic complete AV block, another case had proarrhythmic effect and one patient had to be withdrawn from the study because of gastric irritation. No instance of contractile depression was observed. Accordingly, carbamazepine is a therapeutic alternative for treatment of symptomatic complex ventricular or supraventricular arrhythmias in chronic chagasic patients without evidence of conduction system involvement or with intolerance to other antiarrhythmic drugs.