title: Cardiac resynchronization therapy improves central sleep apnea and Cheyne-Stokes respiration in patients with chronic heart failure.
abstract: OBJECTIVE
  We studied the effects of cardiac resynchronization therapy (CRT) on heart failure (HF) patients with central sleep apnea (CSA).
  
  
  BACKGROUND
  Patients with advanced HF often suffer from CSA with Cheyne-Stokes respiration. Cardiac resynchronization therapy improves myocardial function and exercise capacity in HF patients with conduction disturbances. The relationship between CRT and CSA is currently unknown.
  
  
  METHODS
  Twenty-four patients (7 females; 62 +/- 11 years) with HF, a reduced left ventricular ejection fraction (24 +/- 6%), and left bundle branch block (QRS duration 173 +/- 22 ms) received a CRT device. The number of apneas and hypopneas per hour (apnea-hypopnea index [AHI]) and minimal oxygen saturation (SaO2min) were quantified by cardiorespiratory polygraphy. Fourteen patients showed CSA (AHI >5/h), and 10 patients had an AHI <5/h without CSA. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Data were evaluated before and after 17 +/- 7 weeks of CRT.
  
  
  RESULTS
  In patients with CSA, CRT led to a significant decrease in AHI (19.2 +/- 10.3 to 4.6 +/- 4.4, p < 0.001) and PSQI (10.4 +/- 1.6 to 3.9 +/- 2.4, p < 0.001) without Cheyne-Stokes respiration and to a significant increase in SaO2min (84 +/- 5% to 89 +/- 2%, p < 0.001). There was no significant change in AHI (1.7 +/- 0.7 to 1.5 +/- 1.6), PSQI (2.4 +/- 0.5 to 2.6 +/- 0.9), and SaO2min (90 +/- 2% to 91 +/- 1%) in patients without CSA.
  
  
  CONCLUSIONS
  Cardiac resynchronization therapy leads to a reduction of CSA and to increased sleep quality in patients with HF and sleep-related breathing disorders. This may have prognostic implications in patients receiving CRT.
authors.affiliation: Department of Cardiology, University Hospital, RWTH, Aachen, Germany.
authors.forename: Anil-Martin
authors.initials: AM
authors.lastname: Sinha
authors.forename: Erik C
authors.initials: EC
authors.lastname: Skobel
authors.forename: Ole-Alexander
authors.initials: OA
authors.lastname: Breithardt
authors.forename: Christine
authors.initials: C
authors.lastname: Norra
authors.forename: Kai U
authors.initials: KU
authors.lastname: Markus
authors.forename: Christian
authors.initials: C
authors.lastname: Breuer
authors.forename: Peter
authors.initials: P
authors.lastname: Hanrath
authors.forename: Christoph
authors.initials: C
authors.lastname: Stellbrink
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D002639:Cheyne-Stokes Respiration / Q000503:physiopathology / Q000628:therapy*; D002908:Chronic Disease; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D020182:Sleep Apnea, Central / Q000503:physiopathology / Q000628:therapy*; D013223:Statistics as Topic; D016896:Treatment Outcome