Introduction: Sleep-related breathing disorders occur in 20-30% of Europeans and North Americans, including 10% of sleep apnea syndrome (SAS). A preliminary study suggested that atrial overdrive pacing with a fixed heart rate might alleviate SAS. However, it is not known whether dynamic atrial overdrive pacing alleviates SAS.
Methods: Patients with indications for a dual chamber pacemaker or implantable cardioverter-defibrillator (ICD) were screened for SAS using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. If PSQI was >5, cardio-respiratory polygraphy was performed before and 4 and 7 months after device implantation. Patients were randomized to algorithm ON-OFF (group A) or OFF-ON (group B) and the apnea-hypopnea index (AHI) was measured.
Results: Out of 105 consecutive patients, 46 (44%) had a positive PSQI. This analysis included 12 patients (mean age = 61 +/- 10 years, body mass index 28.9 +/- 6.5 kg/m(2), left ventricular ejection fraction = 38.3 +/- 13.6%; 10 men). All patients suffered from obstructive or mixed SAS. There were no significant differences in PSQI or AHI between baseline and follow-up or between the two study groups. Therefore, the study was terminated ahead of schedule.
Conclusions: The prevalence of obstructive or mixed SAS was high in pacemaker or ICD recipients and reduced left ventricular ejection fraction. In these patients, long-term dynamic atrial overdrive pacing using did not improve PSQI or SAS. Therefore, patients with relevant obstructive or mixed SAS should not be offered atrial pacing therapy.