Respiratory Muscle Strength, the Six-Minute Walk Test and Quality of Life in Chagas Cardiomyopathy

BACKGROUND AND PURPOSE: Patients with heart failure disease develop respiratory and functional limitations and suffer from the negative influence on their quality of life. This study was designed to evaluate respiratory muscle strength and its relationship to functional capacity, quality of life and rate of perceived exertion in patients with Chagas cardiomyopathy. METHODS: We evaluated 32 patients divided into groups with and without Chagas heart disease. We measured the Minnesota Living with Heart Failure Questionnaire, the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), distance walked during the 6-minute walk test, rating of perceived exertion (RPE), heart rate, blood pressure, respiratory rate, oxygen saturation and ejection fraction (EF). RESULTS: The group with Chagas heart disease showed decreased quality of life (overall score: p = 0.001; physical domain: p = 0.002; role-emotional domain: p = 0.031 and general health domain: p < 0.001) and MIP (p < 0.001) when compared with the control group. There was no difference between the distance walked in both groups. The RPE was greater in the group with Chagas heart disease (p = 0.001). The MIP correlated with MEP (r = 0.631, p = 0.009) and EF (r = 0.524, p = 0.037). CONCLUSION: The inspiratory muscle strength is reduced, and the decreased quality of life has a negative influence on the physical and emotional aspects of the patients with Chagas cardiomyopathy. No correlation was found between perceived exertion and the reduction of respiratory muscle strength.