[Electrocardiographic changes in 29 apparently healthy subjects with positive serological tests for Chagas disease].

Of 78 apparently healthy subjects with positive serological tests for Chagas disease, 29 had EKG abnormalities. On direct questioning only two referred dyspnea, one had palpitations and another one dizziness. The most frequent EKG abnormalities were: peaked T waves in 10 cases; ventricular premature beats in 8 patients, right bundle branch block in 7, left bundle branch block in 5, abnormal ST-T segment in 4, atrial fibrillation in 3 cases, left ventricular hypertrophy in 3, and left anterior hemiblock in 3. As has been previously recognized, the EKG changes plus the positive serological tests are the earliest manifestations of Chagas disease.