Effects of an exercise program on the functional capacity of patients with chronic Chagas' heart disease, evaluated by cardiopulmonary testing.

Introduction: Despite all efforts to restrict its transmission, Chagas' disease remains a severe public health problem in Latin America, affecting 8-12 million individuals. Chronic Chagas' heart disease, the chief factor in the high mortality rate associated with the illness, affects more than half a million Brazilians. Its evolution may result in severe heart failure associated with loss of functional capacity and quality of life, with important social and medical/labor consequences. Many studies have shown the beneficial effect of regular exercise on cardiac patients, but few of them have focused on chronic Chagas' heart disease.

Methods: This study evaluated the effects of an exercise program on the functional capacity of patients with chronic Chagas' disease who were treated in outpatient clinics at the Evandro Chagas Institute of Clinical Research and the National Institute of Cardiology, Rio de Janeiro, Brazil. The exercises were performed 3 times a week for 1 h (30 min of aerobic activity and 30 min of resistance exercises and extension) over 6 months in 2010. Functional capacity was evaluated by comparing the direct measurement of the O₂ uptake volume (VO₂) obtained by a cardiopulmonary exercise test before and after the program (p < 0.05).

Results: Eighteen patients (13 females) were followed, with minimum and maximum ages of 30 and 72 years, respectively. We observed an average increase of VO(2peak) > 10% (p = 0.01949).

Conclusions: The results suggest a statistically significant improvement in functional capacity with regular exercise of the right intensity.