[The value of the electrocardiogram in evaluating myocardial function in patients with Chagas' disease].

The authors studied the electrocardiogram of 1004 patients with Chagas' disease. The fit of this observation was the correlation between the electrocardiographic alterations with the cardiac compromise, which was analysed clinically, by thorax X-ray, echocardiogram and stress test. The results show that increased cardiothoracic index, and decreased ejection fraction, decreased difference between systolic blood pressure before the exercise and at the final of the stress test at maximal weight were associated with greater incidence of ventricular premature beat, intraventricular heart block, inactive area, ST-T alteration. chi 2 test shows that these association was significative. The presence of premature ventricular beats and inactive area on the electrocardiographic study seems to determine worse prognosis to the patients since these alterations were more frequent on the patients that died due to Chagas' disease.