Acute effects of continuous positive airway pressure on cardiac sympathetic tone in congestive heart failure

Background-Depressed ventricular performance and neurohormonal activation a re kev pathophysiological features of congestive heart failure (CHF). Altho ugh angiotensin-converting enzyme inhibitors and beta -adrenoceptor blocker s exert beneficial effects in CHF. mortality remains unacceptably high, and the development of further therapeutic approaches is warranted. Recent dat a suggest that continuous positive airway pressure (CPAP) may be of benefit in the treatment of CHF, although the mechanism for this action is incompl etely understood. Methods and Results-In the present study, we examined the effect of short-t erm CPAP (10 cm H2O for 10 minutes) on hemodynamics (Swan Ganz catheter) an d total systemic and cardiac sympathetic activity (norepinephrine spillover method) in 14 CHF patients in New York Heart Association class III. The ap plication of CPAP was associated with a fall in cardiac output (4.8 +/-0.3 to 4.4 +/-0,2 L/min, P <0,05) and a significant reduction in cardiac norepi nephrine spillover (370 +/- 58 to 299 +/- 55 pmol/min; P <0,05), although t otal systemic norepinephrine spillover was unchanged. Conclusion-The short-term application of CPAP results in an inhibition of c ardiac sympathetic nervous activity. Further investigation into the potenti al value of long-term CPAP in CHF patients is warranted.