Atrial Overdrive Pacing for the Obstructive Sleep Apnea–Hypopnea Syndrome

BACKGROUND: The role of atrial overdrive pacing (AOP) in sleep apnea remains uncertain. We prospectively evaluated the effect of AOP after 24 hours and after one month in patients with the obstructive sleep apnea-hypopnea syndrome and compared it with the use of nasal continuous positive airway pressure (n-CPAP). METHODS: We studied 16 patients with a moderate or severe case of the obstructive sleep apnea-hypopnea syndrome (baseline mean apnea-hypopnea index, 49) and normal left ventricular systolic function in whom a dual-chamber pacemaker had been implanted. After 48 hours, the patients were randomly assigned to AOP (pacing at 15 bpm above the spontaneous mean nocturnal heart rate) or backup atrial pacing (pacing at a heart rate below 40 bpm); the latter group began n-CPAP therapy one day later. After one month, the two groups switched therapies and were followed for an additional month. Polysomnographic studies were performed at baseline, on the first night after randomization, at crossover, and at the end of the study. RESULTS: During AOP, no significant changes were observed in any of the respiratory variables measured. The change in the apnea-hypopnea index at one month with AOP was +0.2 (95 percent confidence interval, -2.7 to +2.3; P=0.87). In contrast, all variables improved significantly after one month of n-CPAP (change in the apnea-hypopnea index, -46.3; 95 percent confidence interval, -56.2 to -36.5; P<0.001). CONCLUSIONS: Nasal continuous positive airway pressure therapy is highly effective for the treatment of the obstructive sleep apnea-hypopnea syndrome, whereas AOP has no significant effect.