Overdrive Ventricular Pacing in Pacemaker Recipients with Permanent Atrial Fibrillation and Sleep Apnea

Study Objectives: Cardiac pacing is ineffective in obstructive sleep apnea (SA), but it can alleviate central SA/CheyneStokes respiration (CSA) in patients with heart failure (HF). We examined whether overnight overdrive ventricular pacing (OVP) has an effect on SA in pacemaker recipients with permanent atrial fi(AF). Methods: An apnea-hypopnea index (AHI) ≥ 15 was confi rmed in 28/38 patients screened by fi nger pulse oximetry during overnight ventricular pacing at a backup rate of 40 bpm (BUV40). These patients (23 men, 77.9 ± 7.6 y, BMI 27.6 ± 5.1 kg/m 2 ) were randomly assigned to 2 consecutive nocturnal ventilation polygraphies with BUV40 versus OVP at 20 bpm above the mean nocturnal heart rate observed during screening. Results: During BUV40 versus OVP, (1) mean heart rate was 49 ± 8 versus 71 ± 8 bpm (p < 0.0001) and percent ventricular pacing 36% ± 38% versus 96% ± 6% (p < 0.0001); (2) AHI was 35.4 ± 11.9 versus 32.5 ± 15.5 (p = ns), central AHI 23.9 ± 11.8 versus 19.1 ± 12.7 (p < 0.001), and obstructive AHI 11.6 ± 13.1 versus 13.5 ± 15.9 (p = ns). In 15/28 patients without HF, mean left ventricular ejection fraction (LVEF) was 51% ± 17%, AHI was 37.6 ± 11.0 during BUV40 and 39.0 ± 11.5 during OVP, versus 32.8 ± 12.9 and 24.9 ± 16.5 in 13/28 patients with HF (p = 0.02) and mean LVEF 35% ± 15% (p = 0.01). Between the 2 subgroups, (1) central AHI was 23.6 ± 12.4 during BUV40 and 21.5 ± 14.0 during OVP versus 24.1 ± 11.6 and 16.2 ± 10.7 (p = 0.05); (2) obstructive AHI was 14.0 ± 13.7 during BUV40 and 17.6 ± 16.5 during OVP versus 8.8 ± 12.3 and 8.7 ± 14.3 (p = ns). Conclusions: The prevalence of SA, predominantly central, was high in our pacemaker recipients with permanent AF. In those with HF, a single overnight OVP resulted in modest improvement in central events.