title: A meta-analysis of the effects of atrial overdrive pacing on sleep apnea syndrome.
abstract: BACKGROUND
  Atrial overdrive pacing is a novel method that has been used to treat patients with sleep apnea syndrome (SAS) in many trials. However, the effects of atrial overdrive pacing on SAS are unclear.
  
  
  METHODS
  Studies were retrieved from the PubMed and EMBASE databases (1966 to January 2008), the Central Cochrane Controlled Trials Register (January 2008), and reference lists. Randomized controlled trials were selected that compared atrial overdrive pacing with nonpacing in SAS. Information on study design, patient characteristics, the apnea hypopnea index (AHI), and minimum arterial oxygen saturation (SaO2) was extracted.
  
  
  RESULTS
  Eight trials that included a total of 129 patients were identified. The analysis showed that atrial overdrive pacing, as compared to nonpacing, reduced the AHI and increased the minimum SaO2 significantly in the subgroup of patients who presented predominantly with central sleep apnea syndrome (CSAS) (for AHI, mean difference [MD]=-17.08, 95% confidence interval [CI]: -23.25 to -10.91; for minimum SaO2, MD=4.00, 95% CI: 2.48 to 5.52, respectively). The AHI (MD=-2.94, 95% CI: -5.33 to -0.54) was also significantly reduced in the subgroup of patients who showed predominant obstructive sleep apnea syndrome (OSAS), but the result of the analysis of AHI in OSAS-predominant trials was not robust to the exclusion of some trials. There was weak evidence of an increase in minimum SaO2 in the subgroup in which OSAS was predominant (MD=0.13, 95% CI: -1.18 to 1.45).
  
  
  CONCLUSIONS
  Atrial overdrive pacing appears to be effective in patients with CSAS. The role of atrial overdrive pacing in OSAS remains unclear.
authors.affiliation: Department of Respiratory Medicine, Peking University People's Hospital, Beijing, China. wengcuilian20051@sina.com
authors.forename: Cui-Lian
authors.initials: CL
authors.lastname: Weng
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.forename: Yan-Liang
authors.initials: YL
authors.lastname: Ma
authors.forename: Quan-Ying
authors.initials: QY
authors.lastname: He
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods* / Q000706:statistics & numerical data*; D006325:Heart Atria; D006801:Humans; D017063:Outcome Assessment, Health Care; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*; D016896:Treatment Outcome