Effect of ventilatory support on functional capacity in patients with heart failure: a pilot study.

BACKGROUND Heart failure (HF) is an important public health problem, of which main clinical symptoms are dyspnea and fatigue. Noninvasive ventilatory support has been used as adjuvant therapy in cardiac rehabilitation in order to improve the functional capacity of patients. OBJECTIVE To evaluate the functional capacity of patients with HF submitted to ventilatory support. METHODS We evaluated the sociodemographic information, as well as data on quality of life, blood pressure (BP), peripheral oxygen saturation (SpO2), dyspnea, lactate concentration before and after the 6-minute walk test (6MWT) and the distance walked by patients of both sexes with chronic heart failure (CHF), with left ventricular ejection fraction (LVEF) < 45.0% , randomized in two groups: control and CPAP (the group used CPAP - 10 cmH2O for 30 minutes). RESULTS A total of 12 patients, of which 8 were males, with CHF functional class II and III (NYHA) participated in the study. The patients had mean LVEF of 35.3 ± 8.7 and mean age was 46.3 ± 10.3 years. When comparing the control group with the CPAP group at the end of the 6th minute, there was a significant difference between the groups regarding SpO2 values ( CONTROL 93.6 ± 1.5 % vs CPAP: 96.1±1.8%; p = 0.027), index of dyspnea ( CONTROL 13.1 ± 1.16 vs CPAP: 11 ± 0.8; p = 0.009), lactate concentration ( CONTROL 3.3 ± 0.7 mmol/l vs CPAP: 2.3 ± 0.5 mmol/l; p = 0.025) and distance walked at the 6MWT (CONTROL: 420.6 ± 73.8 m vs CPAP: 534 ± 89.91 m; p = 0.038). CONCLUSION The previous use of the CPAP had beneficial effects on SpO2, index of dyspnea, lactate concentration, double product and the distance walked at the 6MWT in patients with CHF when performing the 6MWT.