Diastolic function and functional capacity after a single session of continuous positive airway pressure in patients with compensated heart failure

OBJECTIVE: The effects of acute continuous positive airway pressure therapy on left ventricular diastolic function and functional capacity in patients with compensated systolic heart failure remain unclear. METHODS: This randomized, double-blind, placebo-controlled clinical trial included 43 patients with heart failure and a left ventricular ejection fraction <0.50 who were in functional classes I-III according to the New York Heart Association criteria. Twenty-three patients were assigned to continuous positive airway pressure therapy (10 cmH2O), while 20 patients received placebo with null pressure for 30 minutes. All patients underwent a 6-minute walk test (6MWT) and Doppler echocardiography before and immediately after intervention. Clinicaltrials.gov: NCT01088854. RESULTS: The groups had similar clinical and echocardiographic baseline variables. Variation in the diastolic function index (e′) after intervention was associated with differences in the distance walked in both groups. However, in the continuous positive airway pressure group, this difference was greater (continuous positive airway pressure group: Δ6MWT = 9.44+16.05×Δe′, p = 0.002; sham group: Δ6MWT = 7.49+5.38×Δe′; p = 0.015). There was a statistically significant interaction between e′ index variation and continuous positive airway pressure for the improvement of functional capacity (p = 0.020). CONCLUSIONS: Continuous positive airway pressure does not acurately change the echocardiographic indexes of left ventricle systolic or diastolic function in patients with compensated systolic heart failure. However, 30-minute continuous positive airway pressure therapy appears to have an effect on left ventricular diastolic function by increasing functional capacity

Chronic obstructive pulmonary disease severity and its association with obstructive sleep apnea syndrome: impact on cardiac autonomic modulation and functional capacity

Katiany Thays Lopes Zangrando,1 Renata Trimer,2 Luiz Carlos Soares de Carvalho Jr,1 Guilherme Peixoto Tinoco Ar&ecirc;as,1 Fl&aacute;via Cristina Rossi Caruso,1 Ramona Cabiddu,1 Meliza Goi Roscani,3 Fab&iacute;ola Paula Galhardo Rizzatti,3 Audrey Borghi-Silva1 1Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of S&atilde;o Carlos, S&atilde;o Carlos, S&atilde;o Paulo, Brazil; 2Physical Education and Health Department, University of Santa Cruz do Sul, Santa Cruz do Sul, Rio Grande do Sul, Brazil; 3Medicine Department, Federal University of S&atilde;o Carlos, S&atilde;o Carlos, S&atilde;o Paulo, Brazil Background: The study was conducted to determine the impact of chronic obstructive pulmonary disease (COPD) in association with obstructive sleep apnea syndrome (OSAS) on cardiac autonomic control and functional capacity. Subjects and methods: The study was a cross-sectional prospective controlled clinical study. Heart rate variability indices of 24 COPD (n = 12) and COPD+OSAS (n = 12) patients were evaluated and compared by electrocardiographic recordings acquired during rest, active postural maneuver (APM), respiratory sinus arrhythmia maneuver (RSA-m), and the 6-minute walk test (6MWT). Results: The COPD group presented higher parasympathetic modulation during APM when compared to the COPD+OSAS group (P = 0.02). The COPD+OSAS group presented higher sympathetic modulation during RSA-m when compared to the COPD group (P = 0.00). The performance during 6MWT was similarly impaired in both groups, despite the greater severity of the COPD group. Conclusion: Subjects with COPD+OSAS present marked sympathetic modulation, and the presence of OSAS in COPD subjects has a negative impact on functional capacity regardless of the severity of lung disease. Keywords: COPD, OSAS, COPD+OSAS, functional capacit