Recently, in a randomized trial in 55 patients, CPAP therapy for 3 months improved ventricular function and reduced sympathetic activity in patients with heart failure and obstructive sleep apnea (OSA). Likewise,
CPAP therapy in OSA patients reduced daytime blood pressure and heart
rate, and was associated with a significant reduction in left ventricular end-systolic dimensions and increases in ejection fraction."
Source: http://eurheartjsupp.oxfordjournals.