[High frequency electrocardiography in the early diagnosis of myocardial damage in patients with Chagas disease].

The present study determines the degree of usefulness provided by the qualitative analysis of the high frequency EKG with Mc Fee's triaxial system in the detection of myocardial damage during the incipient stages of Chagas disease. The results show that only the descending phase of the wave which corresponds to the vertical axis, i.e. Y, detects some kind of cardiac damage in the initial stages of disease with a high specificity, if normal values of 0-3 notches are taken, but in detriment of the sensitivity which is relatively low. This method did not prove to be useful in the longitudinal study of chagasic patients. It is a method which is very simple to perform with an inter-observer variability of 7%.