[Normal maximal functional capacity in patients with congestive heart failure due to Chagas' cardiomyopathy].

PURPOSE

To compare patients with heart failure due to Chagas' cardiomyopathy and maximal oxygen consumption greater than 20mL/kg-1/min-1 to normal individuals.

METHODS

We studied 104 male patients with heart failure due to Chagas' cardiomyopathy, functional classe II-IV, age 18 to 65 years (40.3 +/- 9.0), and 23 normal sedentary male individuals (GI) age 17 to 51 years (35 +/- 8.7). Maximal oxygen consumption (VO2max) was obtained using a Beckman metabolic measurement cart, and left ventricular ejection fraction (EF) by conventional transthoracic echocardiography. Comparisons between means were made with t-test.

RESULTS

Thirty seven patients (35.6%) presented VO2max above 20mL/kg-1/min-1 (G2), with values ranging from 20.5 to 30 (24.5 +/- 2.9) and EF between 19 and 63% (42 +/- 11.7). GI had VO2max between 21 and 42mL/kg-1/min-1 (33.3 +/- 5.6) and EF between 70 and 82% (75.1 +/- 3.2). Ages were not significantly different for the two groups (p = 0.1136). VO2max and EF were lower in G2, and this was statistically significant (p < 0.0001).

CONCLUSION

These results indicate that patients with congestive heart failure due to Chagas disease may show values of VO2max, greater than 20mL/kg-1/min-1 which does not mean that they have normal maximal functional capacity.