title: [Acute effects of cardiac resynchronization therapy on breathing during sleep in patients with severe chronic heart failure--a pilot study].
abstract: BACKGROUND
  Sleep-related breathing disorders (SDB), especially Cheyne-Stokes respiration (CSR), have prognostic relevance in patients with chronic heart failure (CHF). Thus, we investigated acute effects of cardiac resynchronization therapy on breathing during sleep.
  
  
  METHODS
  Beside a cardiopulmonary investigation, breathing during sleep was analysed polygraphically/polysomnographically on the night before and during the second night after implantation of a biventricular pacemaker for cardiac resynchronization.
  
  
  METHODS
  We investigated 16 consecutive patients with severe CHF (NYHA class III-IV) and widened QRS complexes (QRS > 150 ms) with the indication for cardiac resynchronization therapy independent of this study.
  
  
  RESULTS
  Cardiac resynchronization therapy shortened the QRS time in each and every patient (QRS: 167.3 +/- 21.7 ms to 113.0 +/- 19.0 ms; p < 0.001) as a marker for successful resynchronization. Initially, SDB were diagnosed in 11 of the 16 patients studied (69 %), with 7 patients having CSR (44 %) and 4 patients (25 %) having CSR and obstructive sleep apnoea. With cardiac resynchronization therapy, no significant acute changes were seen regarding nocturnal breathing/breathing disorder, heart frequency, or oxygen saturation.
  
  
  CONCLUSIONS
  The established positive effects of cardiac resynchronization therapy are rather due to a chronic improvement of cardiopulmonary interactions (remodelling, circulatory time, or chemosensitivity) than to acute effects, as investigated in this study.
authors.affiliation: Medizinische Klinik III, Pneumologie, Allergologie, Schlaf- und Beatmungsmedizin, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bochum. hans-werner.duchna@rub.de
authors.forename: H-W
authors.initials: HW
authors.lastname: Duchna
authors.forename: M
authors.initials: M
authors.lastname: Orth
authors.forename: P
authors.initials: P
authors.lastname: Karschuck
authors.forename: G
authors.initials: G
authors.lastname: Schultze-Werninghaus
authors.forename: T
authors.initials: T
authors.lastname: Lawo
mesh_terms: D000208:Acute Disease; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D002908:Chronic Disease; D005260:Female; D006333:Heart Failure / Q000517:prevention & control*; D006801:Humans; D008297:Male; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000209:etiology*; D016896:Treatment Outcome