title: Effectiveness of short-term treatment with nocturnal oxygen therapy for central sleep apnea in patients with congestive heart failure.
abstract: OBJECTIVE
  To evaluate the short term effects of inhalation of oxygen at night in 51 patients with congestive heart failure (CHF) and sleep apnea syndrome (SAS).
  
  
  METHODS
  Fifty-one patients with stable CHF (31 males, 20 females, mean age 79.0 +/- 11.9 years; brain natriuretic peptide level of > 100 pg/ml) were evaluated between September 2003 and August 2004, using a Morpheus monitor. The complication rate of SAS in patients with CHF was assessed and apnea hypopnea index, oxygen desaturation index 3%, heart rate, and autonomic nerve activity under room air compared to supplemental O2 (2 l/min) over two consecutive nights.
  
  
  RESULTS
  Thirty-eight (75%)of the CHF patients had SAS. Of these SAS patients, 49% suffered from central SAS and 51% had obstructive SAS. Apnea hypopnea index and oxygen desaturation index 3% improved remarkably with supplemental oxygen (p < 0.001), in particular, the central SAS group demonstrated prominent improvement (p < 0.001). Obstructive SAS patients exhibited no significant changes (p = 0.3356), but tended to exacerbate the episodes of sleep apnea. Total heart rate was decreased (p = 0.0079). Nevertheless, heart rate variability analysis showed little effect of nocturnal oxygen therapy on the autonomic nervous system during sleeping.
  
  
  CONCLUSIONS
  Nocturnal oxygen therapy improved the number of sleep apnea episodes and decreased total heart rate during sleep time for the CHF patients with central SAS, despite little influence on the autonomic nervous system, based upon assessment of heart rate variability. Obstructive SAS might exacerbate the episodes of sleep apnea.
authors.affiliation: Department of Cardiology, Heart Center, Ikegami General Hospital, Tokyo. mike.s@ninus.ocn.ne.jp
authors.forename: Mamoru
authors.initials: M
authors.lastname: Sakakibara
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Sakata
authors.forename: Kazutane
authors.initials: K
authors.lastname: Usui
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Hayama
authors.forename: Shigetaka
authors.initials: S
authors.lastname: Kanda
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Wada
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Matsui
authors.forename: Yukio
authors.initials: Y
authors.lastname: Suto
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Shimura
authors.forename: Teruhisa
authors.initials: T
authors.lastname: Tanabe
mesh_terms: D000368:Aged; D005260:Female; D006333:Heart Failure / Q000150:complications*; D006801:Humans; D008297:Male; D010102:Oxygen Inhalation Therapy; D020182:Sleep Apnea, Central / Q000503:physiopathology / Q000628:therapy*