[Prevalence of electrocardiographic abnormalities in 2,000 aged and non-aged chagasic patients]

To assess the prevalence of main electrocardiographic alterations in chagasic patients at University of Triângulo Mineiro Medical School, and compare such alterations between aged and non-aged patients.

Electrocardiograms (ECG) of 2,000 chagasic patients were interpreted. Age, color, sex and concomitant systemic hypertension, congestive heart failure (CHF) and megaesophagus and/or megacolon were registered. Chi-square test was employed to compare aged (60 years or more; n = 378) and non-aged (age less than 60 years; n = 1622) chagasics.

ECG were normal in 9.6% of the patients. The main alterations were: ventricular premature complexes (VPC) 42.2%, left ventricular enlargement (LVE) 38.8%, right bundle branch block (RBBB) 32.4%, left anterior hemiblock 29.2% and ventricular repolarization changes 28.2%. The aged group exhibited greater (p < 0.05) proportion of male patients (1.7:1 vs 1.1:1), white than non-white (3.6:1 vs 2.2:1) and larger percentages (p < 0.01) of systemic hypertension (18.2 vs 7.5) and CHF (26.4 vs 12.0). The following alterations were significantly more common on aged chagasic: VPC (62.7 vs 37.5), LVE (43.4 vs 37.1), atrial fibrillation (19.6 vs 5.5), supraventricular premature complexes (11.9 vs 5.2), electrically inactive zone (9.5 vs 6.6), wandering atrial pacemaker (4.5 vs 2.2) and 2nd-degree atrioventricular (AV) block (2.9 vs 1.5). The non-aged chagasic had greater percentage (p < 0.05) than aged group of normal ECG (10.7 vs 5.0), RBBB (34.1 vs 24.9) and 1st degree AV block (9.7 vs 6.3).

There was a high prevalence of ECG alterations in chagasic patients seeking medical attention. The different frequencies of those alterations between aged and non-aged chagasic may result of conditions more frequently seen in aged, like ischemic heart disease, CHF and systemic hypertension or to a probable more severe cardiac denervation in non-aged chagasic.