Acute Effect of Continuous Positive Airway Pressure in Heart Failure

Acute Effect of Continuous Positive Airway Pressure on Left Ventricular Diastolic Function and Exercise Tolerance in Compensated Heart Failure

Acute effects of CPAP on diastolic function in patients with compensated heart failure (CHF) are unknown. The investigators hypothesized that acutely CPAP improves diastolic function, which is associated with increases exercise tolerance. Objective: To evaluate the acute effects of CPAP on functional capacity and diastolic indices of patients with CHF. This is a randomized trial including 44 patients with compensated heart failure (functional classes II or III, NYHA). Patients will be allocated in CPAP(CPAP with 10cmH2O) or simulated CPAP (null pressure) after computed randomization, in a 1:1 ratio. All subjects shall complete a 6-minute walk test (6MWT) before and after CPAP (30 minutes; 10 cm H2O pressure). Doppler-echocardiogram will be performed before and at the end of CPAP. Wilcoxon or paired t tests were used to compare results, with significance level at p < 0.05.

Doppler-derived isovolumetric time will be measured before and after intervention (CPAP). A decreasing in isovolumetric time after CPAP will be interpretated as an improvement in myocardial relaxation

subjects will be tested before and after procedure (CPAP). An increasing distance after procedure will be interpretated as improved tolerance to exercise

Inclusion Criteria: functional class II or III (NYHA)heart failure agreement to participate in the study absence of acute exacerbation of dyspnea intact upper airway Exclusion Criteria: valvular heart disease chest pain or unstable angina acute myocardial infarction in the prior month uncontrolled hypertension atrial fibrillation or other arrhythmias acute infection orthopedic limitations intolerance to CPAP mask

Bradley TD, Logan AG, Kimoff RJ, Series F, Morrison D, Ferguson K, Belenkie I, Pfeifer M, Fleetham J, Hanly P, Smilovitch M, Tomlinson G, Floras JS; CANPAP Investigators. Continuous positive airway pressure for central sleep apnea and heart failure. N Engl J Med. 2005 Nov 10;353(19):2025-33. doi: 10.1056/NEJMoa051001.

Bussoni MF, Guirado GN, Matsubara LS, Roscani MG, Polegato BF, Minamoto ST, Bazan SG, Matsubara BB. Diastolic function and functional capacity after a single session of continuous positive airway pressure in patients with compensated heart failure. Clinics (Sao Paulo). 2014;69(5):354-9. doi: 10.6061/clinics/2014(05)010.