[Effect of atrial pacing on the sleep apnea syndrome in elderly patients].

OBJECTIVE

To evaluate the efficacy of atrial pacing to increase the heart rate during sleep in elderly patients with sleep apnea syndrome.

METHODS

Sixteen elderly patients with central type or obstructive type sleep apnea received permanent atrial-synchronous ventricular pacemakers for symptomatic sinus bradycardia were analysed in this study. All patients received polysomnographic evaluations for 3 consecutive nights. All patients were evaluated at the base-line, and then were randomly divided into 2 groups at the first night. In the following 2 nights, one group was monitored in spontaneous rhythm model and the other in dual-chamber pacing model with atrial overdrive (increasing by 15 beats per minute on the basic rate of the mean nocturnal sinus), and then the two groups were switched at the third night. The total duration and number of episodes of sleep apnea or hypopnea were analyzed, and compared between the two models.

RESULTS

The mean 24 h sinus rate in the spontaneous rhythm mode was 55+/-9 beats per minute at the base line, as compared in the 72+/-4 beats per minute in the atrial overdrive pacing model. There was statistic significant difference between the 2 models (P<0.05). There was no difference in the total duration of sleep between spontaneous rhythm model and atrial overdrive pacing model [(322+/-48) minutes vs (330+/-52) minutes, P>0.05 ]. The hypopnea index reduced from 9+/-3 in the spontaneous rhythm model to 3+/-3 in the atrial overdrive pacing model (P<0.01). The index of apnea and hypopnea was 28+/-21 in the spontaneous rhythm model, as compared with 10+/-13 in the atrial overdrive pacing model (P<0.01).

CONCLUSION

Atrial overdrive pacing can significantly reduce the number of episodes of central type or obstructive type sleep apnea, but doesn't decrease the total sleep time in elderly patients with sleep apnea syndrome.