[Maximal functional capacity and diastolic function in patients with cardiomyopathy due to Chagas' disease without congestive heart failure].

PURPOSE To identify early cardiac dysfunctions in asymptomatic patients with Chagas' cardiomyopathy. METHODS We studied 38 male individuals: control group consisting of 20 sedentary normal individuals and Chagas' group, of 18 asymptomatic patients with Chagas' disease, with suggestive electrocardiographic alterations and normal fractional shortening (FS) on echocardiogram. Both groups were submitted to evaluation of the maximal functional capacity, with measurements of maximal O2 consumption (VO2max), O2-pulse rate (PO2max), maximal ventilation (VEmax), maximal heart rate (HRmax), and anaerobic threshold of the VO2max (VO2-AT). Left ventricular diastolic function was evaluated by conventional echocardiography (E wave, A wave and E/A ratio). RESULTS No significant differences occurred between the two groups with regard to FS (p = 0.212) and age means (p = 0.060). The 2 groups were significantly different (p < 0.001) regarding the parameters VO2max, PO2max, VEmax, HRmax and VO2-AT, E wave and E/A ratio. There was no difference (p = 0.520) in A wave. CONCLUSION Impaired ventricular function may account for the above mentioned differences, a consequence of both systolic and diastolic dysfunctions.