Alterações eletrocardiográficas durante e após tratamento com benzonidazol em fase aguda de doença de Chagas autóctone da Amazônia brasileira

Abstract

ABSTRACTThis article aims to assess the cardiac impairment associated with acute infections by Trypanosoma considering conduction abnormalities and cardiac rhythm during the acute phase of disease and after treatment in a case series study of Chagas' disease indigenous to the Amazon. The individuals included in this study were grouped into two cohorts: cohort I comprised patients undergoing the acute stage of the disease; and cohort II included the same patients re-evaluated after an average period of 3.9 years of treatment. The electrocardiographic evaluation of the individuals in cohort I was based both on restored electrocardiograms that underwent a new reading and on electrocardiograms performed prospectively. All patients were treated with benznidazole on a regular basis. A total of 179 individuals that developed acute Chagas disease in the period between 1992 and 2005 were assessed. During the acute stage of disease, 47.7% of the electrocardiographic tracings were normal, and 52.3% displayed abnormalities. The diffuse changes in ventricular repolarization and low QRS voltage were the main abnormalities found. Cardiac impairment characterized by myopericarditis was observed in 39.1% of the patients, and 24.3% (17/70) of the cases were considered severe. The electrocardiographic changes were more frequent after treatment of patients who had shown electrocardiographic abnormalities during the acute phase, when compared to those who had not. Five other individuals who were diagnosed late and presented with diffuse myocarditis during the acute phase had a poor disease outcome because they progressed to a cardiac disease characterized by lesions typical of chronic cardiopathy.Keywords: Acute Disease; Chagas Disease; Myocarditis; Cohort Studies.