Doppler tissue imaging to evaluate early myocardium damage in patients with undetermined form of Chagas' disease and normal echocardiogram.

Abstract

Chagas' disease can lead to severe and potentially lethal damage of cardiac function. Thus, the identification of contractile abnormalities in asymptomatic patients can be important for risk stratification in those patients. Doppler tissue imaging (DTI) is a new diagnostic modality for the study of regional and longitudinal contractility of the left ventricle. However, DTI has not been used for the assessment of Chagas' cardiopathy. The purpose of this study was to identify abnormalities related to longitudinal contractility by means of DTI in patients with an undetermined form of Chagas' disease and with normal echocardiogram and Doppler studies. Forty patients were studied, including 21 chagasic ones with normal electrocardiographic, radiologic, and echocardiographic studies, and 19 normal control individuals. All of the patients were submitted to DTI to evaluate longitudinal contractility in the various myocardial segments, including assessment of systolic and diastolic velocities and isovolumic contraction time (IVCT). Similar values were observed among the various systolic function rates in both groups, except for the IVCT along the septal wall, which was significantly higher in the chagasic group. DTI enabled the early detection of contractile abnormalities in patients with an undetermined form of Chagas' disease and with normal echocardiogram. Such abnormalities were particularly striking in the interventricular septum. The present study could be useful in risk stratification for those patients.