title: Impact of sleeping position on central sleep apnea/Cheyne-Stokes respiration in patients with heart failure.
abstract: BACKGROUND
  The present study determines the influence of sleeping position on central sleep apnea (CSA) in patients with heart failure (HF).
  
  
  METHODS
  The apnea/hypopnea index (AHI) during different body positions while asleep was examined by cardiorespiratory polygraphy in 71 patients with HF (ejection fraction <45%).
  
  
  RESULTS
  Twenty-five of the patients having predominantly CSA (central apnea index 10/h) with a lower obstructive apnea index (<5/h) were assigned to groups with positional (lateral to supine ratio of AHI <50%, n=12) or non-positional (ratio > or = 50%, n=13) CSA. In the non-positional group the BNP level was higher, the ejection fraction was lower and the trans-tricuspid pressure gradient was higher than in the positional group. Multiple regression analysis revealed more advanced age (p=0.006), log(10)BNP (p=0.017) and lung-to-finger circulation time (p=0.020) as independent factors of the degree of positional CSA. Intensive treatment for HF changed CSA from non-positional to positional in all eight patients tested. Single night of positional therapy reduced CSA (p<0.05) and BNP level (p=0.07) in seven positional patients.
  
  
  CONCLUSIONS
  As cardiac dysfunction progresses, severity of CSA also increases and positional CSA becomes position-independent. Positional therapy could decrease CSA, thereby having a valuable effect on HF.
authors.affiliation: Second Department of Internal Medicine, Toyama University Hospital, Toyama, Japan. sjoho@med.u-toyama.ac.jp
authors.forename: Shuji
authors.initials: S
authors.lastname: Joho
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Oda
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Hirai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
mesh_terms: D000368:Aged; D002639:Cheyne-Stokes Respiration / Q000503:physiopathology* / Q000628:therapy; D004452:Echocardiography; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D017286:Polysomnography; D011187:Posture; D012119:Respiration; D012890:Sleep / Q000502:physiology; D020182:Sleep Apnea, Central / Q000503:physiopathology* / Q000628:therapy; D013318:Stroke Volume / Q000502:physiology