Impact of sleeping position on central sleep apnea/Cheyne-Stokes respiration in patients with heart failure.

BACKGROUND

The present study determines the influence of sleeping position on central sleep apnea (CSA) in patients with heart failure (HF).

METHODS

The apnea/hypopnea index (AHI) during different body positions while asleep was examined by cardiorespiratory polygraphy in 71 patients with HF (ejection fraction <45%).

RESULTS

Twenty-five of the patients having predominantly CSA (central apnea index 10/h) with a lower obstructive apnea index (<5/h) were assigned to groups with positional (lateral to supine ratio of AHI <50%, n=12) or non-positional (ratio > or = 50%, n=13) CSA. In the non-positional group the BNP level was higher, the ejection fraction was lower and the trans-tricuspid pressure gradient was higher than in the positional group. Multiple regression analysis revealed more advanced age (p=0.006), log(10)BNP (p=0.017) and lung-to-finger circulation time (p=0.020) as independent factors of the degree of positional CSA. Intensive treatment for HF changed CSA from non-positional to positional in all eight patients tested. Single night of positional therapy reduced CSA (p<0.05) and BNP level (p=0.07) in seven positional patients.

CONCLUSION

As cardiac dysfunction progresses, severity of CSA also increases and positional CSA becomes position-independent. Positional therapy could decrease CSA, thereby having a valuable effect on HF.