title: Nocturnal overdrive pacing for the treatment of sleep apnea syndrome.
abstract: OBJECTIVE
  We investigated the effect of 1 week of nocturnal overdrive pacing (NOP) on the apnea-hypopnea index (AHI) in patients with a chronically implanted pacemaker and diagnosed during a screening phase with sleep apnea.
  
  
  METHODS
  Randomized, single-blind, crossover study.
  
  
  METHODS
  University medical centers in Zürich, Switzerland, and Berlin, Germany.
  
  
  METHODS
  Nineteen patients with mild to severe sleep apnea/hypopnea (16 men, mean age = 68.8 +/- 11.4 years) participated. The individuals did not suffer from permanent atrial arrhythmia, did not use continuous positive airway pressure, and had been implanted with atrial or dual-chamber pacemakers.
  
  
  METHODS
  Nocturnal lower rates were 45 and 75 beats per minute (bpm) at night for the control and NOP arms, respectively, and daytime lower rates were 60 bpm. Subjects were in each arm for 1 week.
  
  
  RESULTS
  Heart-rate increase from control (61 +/- 9 bpm) to NOP (78 +/- 4 bpm) followed by significant reduction in circulation time (24.6 seconds control, 20.7 seconds NOP; p = .04) resulted in no significant change in AHI (26.8 +/- 17.1/h control, 23.0 +/- 16.7/h NOP; p = .49). Seven subjects characterized by a higher hypopnea index, less stage 1 and 2 sleep, and less slow-wave sleep improved at least 1 AHI severity level with NOP, mainly attributable to reduction of hypopneas.
  
  
  CONCLUSIONS
  NOP over a period of 1 week followed by a reduction in circulation time did not improve AHI in patients with SA. Whether an improvement by 1 AHI severity level in a specific subset of patients reflects a true response remains to be elucidated by further studies.
authors.affiliation: Charité University Medical Centre, Medizinische Klinik mit Schwerpunkt, Kardiologie, Angiologie, Pneumologie, Schumannstr. 20/21, 10117 Berlin, Germany. christoph.melzer@charite.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Melzer
authors.forename: Ingo
authors.initials: I
authors.lastname: Fietze
authors.forename: Firat
authors.initials: F
authors.lastname: Duru
authors.forename: Martin
authors.initials: M
authors.lastname: Glos
authors.forename: Kristina
authors.initials: K
authors.lastname: Lemola
authors.forename: Konrad
authors.initials: K
authors.lastname: Bloch
authors.forename: Mark
authors.initials: M
authors.lastname: Erickson
authors.forename: Yong
authors.initials: Y
authors.lastname: Cho
authors.forename: Toby
authors.initials: T
authors.lastname: Markowitz
authors.forename: Heinz
authors.initials: H
authors.lastname: Theres
mesh_terms: D045422:Continuous Positive Airway Pressure; D018592:Cross-Over Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data; D017286:Polysomnography / Q000379:methods; D012720:Severity of Illness Index; D016037:Single-Blind Method; D012891:Sleep Apnea Syndromes / Q000453:epidemiology* / Q000628:therapy*; D012895:Sleep, REM / Q000502:physiology; D016896:Treatment Outcome