Nocturnal overdrive pacing reduces circulation delay

Sleep apnea affects 24% of men and 9% of women. Circulation delay (CD) is the time from end of an apnea ro oxygen saturation nadir. To evaluafe efleects of cardiac pacing on sleep apnea, I9 patients were enrolled in a WO center, single blind, randomized crossover study comparing Nocturnal Overdrive Pacing (NOP, 7.5 bpm lower night rate) to Control (45 bpm lower night rate). Patients underwent two sleep studies measuring Apnea- Hypupnea Index (AHI, [# (apneas+hypopneus)/hour of sleep] and finger oxygen saturation. CD WAS measured with an adaptive window in 14 patients. NUP improved AHI 210 eventshour in 4 {Responders), and not in 10 (Non-responders). NUP decreased CD in all patients. CD was 25.633.5 sec, Control, and 20.9H.7 sec, NUP, (p=0.03). Changes in CD were not different in Responders YS. Non-responders (4.8G.O sec vs. 4.6G.9 sec, p=0.9). NUP reduced CD, however, CD did not predict relative changes in severity of sleep apnea as measured by AHI.