[Acute effects of cardiac resynchronization therapy on breathing during sleep in patients with severe chronic heart failure--a pilot study].
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.
Duchna
H-W
HW
Medizinische Klinik III, Pneumologie, Allergologie, Schlaf- und Beatmungsmedizin, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bochum. hans-werner.duchna@rub.de
Orth
M
M
Karschuck
P
P
Schultze-Werninghaus
G
G
Lawo
T
T
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