Effect of pacing mode on sleep disturbance

The relationship between pacing mode and sleep is not yet known, and therefore polysomnography was used to evaluate the effect. A total of 16 patients (8 men and 8 women; mean age, 72 +/- 9 years) with DDD pacemakers made up the study population. Of these 16 patients, 8 patients had complete AV block and 8 patients had sick sinus syndrome. The recording was done twice in VVI and DDD modes. Between VVI mode and DDD mode, sleep latency time (VVI mode: 38 +/- 25, DDD mode 23 +/- 27 min), frequency of temporary waking (8.3 +/- 6.7, 3.7 +/- 2.9 times), the number of episodes of apnea (59 +/- 84, 36 +/- 55 times, the apnea-hypopnea index (AHI) (15 +/- 18, 10 +/- 13), and efficacy of sleep (72% +/- 10%, 81% +/- 11%) were significantly different. Also, the apnea index improved significantly in DDD mode. There was no significant difference in total sleep time and in total duration of temporary waking between the two groups. From the study results, a reduction in sleep disturbance was achieved when DDD pacing mode was chosen, rather than VVI mode. Furthermore, efficacy of sleep also improved significantly compared with VVI mode. Interestingly, sleep apnea syndrome in four patients with AHI > or = 15 notably ameliorated when DDD mode was chosen; however, the mechanism involved in amelioration is still ambiguous and needs further assessment.