title: The effect of successful heart transplant treatment of heart failure on central sleep apnea.
abstract: OBJECTIVE
  Central sleep apnea (CSA) associated with Cheyne-Stokes respiration in patients with congestive heart failure (CHF) is thought to be an acquired pattern of respiratory control instability related, at least in part, to elevated sympathetic nervous system activity. The effect of restoring heart function to normal with heart transplantation in patients with CHF and CSA has only been reported within weeks of the transplant and with varying results. The purpose of the study was to evaluate the impact of successful heart transplant on sympathetic nervous system activity and CSA severity in patients with CHF.
  
  
  METHODS
  Controlled prospective trial.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Twenty-two patients with CHF (13 patients with CSA, and 9 patients with no sleep-disordered breathing [SDB]).
  
  
  METHODS
  Polysomnography, left ventricular ejection fraction (LVEF), and overnight urinary norepinephrine excretion (UNE) were measured before and > 6 months after successful heart transplantation.
  
  
  RESULTS
  In the CSA group, there was a fall in apnea-hypopnea index (AHI) [mean +/- SD, 28 +/- 15 to 7 +/- 6/h; p < 0.001] and UNE (48.1 +/- 30.9 to 6.1 +/- 4.8 nmol/mmol creatinine, p < 0.001) associated with normalization of LVEF (19.2 +/- 9.3% to 53.7 +/- 6.1%, p < 0.001) at 13.2 +/- 8.3 months following heart transplantation. Of the CSA group following transplantation, seven patients had no SDB (AHI < 5/h), three patients had persistent CSA (AHI, 12.3 +/- 0.9/h) and four patients acquired obstructive sleep apnea (OSA) [AHI, 11.2 +/- 7.4/h]. In comparison, none of the control group acquired CSA or OSA after transplantation.
  
  
  CONCLUSIONS
  We conclude that CSA may persist despite normalization of heart function and sympathetic nerve activity.
authors: Monash University, Melbourne, VIC, Australia.
authors: Darren R
authors: DR
authors: Mansfield
authors: Peter
authors: P
authors: Solin
authors: Teanau
authors: T
authors: Roebuck
authors: Peter
authors: P
authors: Bergin
authors: David M
authors: DM
authors: Kaye
authors: Matthew T
authors: MT
authors: Naughton
mesh_terms: D000328:Adult; D002639:Cheyne-Stokes Respiration / Q000150:complications / Q000503:physiopathology; D003404:Creatinine / Q000652:urine; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000652:urine; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D011446:Prospective Studies; D020182:Sleep Apnea, Central / Q000150:complications / Q000503:physiopathology*; D013318:Stroke Volume; D013564:Sympathetic Nervous System / Q000503:physiopathology; D016277:Ventricular Function, Left
chemical_list: D003404:Creatinine; D010100:Oxygen; D009638:Norepinephrine