title: The effect of biventricular pacing on cardiac function after weaning from cardiopulmonary bypass in patients with reduced left ventricular function: a pressure-volume loop analysis.
abstract: OBJECTIVE
  Patients with severely reduced left ventricular function undergoing coronary artery bypass grafting have increased complication rates. We hypothesized that temporary postoperative atrial synchronous biventricular pacing would improve left ventricular function after cardiopulmonary bypass.
  
  
  METHODS
  A left ventricular pressure-volume catheter was placed in 21 patients undergoing coronary artery bypass grafting (ejection fraction 29% +/- 5%). Pressure-volume loops were obtained after weaning from cardiopulmonary bypass with atrial synchronous biventricular, left ventricular, and right ventricular outflow tract pacing and atrial-only stimulation at 90 beats/min.
  
  
  RESULTS
  Steady-state systolic and preload-independent parameters were superior for atrial synchronous biventricular and left ventricular pacing and atrial-only pacing relative to atrial synchronous right ventricular outflow tract pacing (P < .05). Diastolic parameters, excepting maximum negative rate of left ventricular pressure change, were unaffected. No significant differences were observed between atrial synchronous biventricular and left ventricular pacing and atrial-only pacing. Systolic dyssynchrony was significantly lower for atrial synchronous biventricular pacing (21% +/- 5%), atrial synchronous left ventricular pacing (20% +/- 6%), and atrial-only pacing (20% +/- 6%) versus atrial synchronous right ventricular outflow tract pacing (25% +/- 7%, P < .05). Atrioventricular interval during atrial-only stimulation was positively correlated with difference in stroke work between atrial synchronous biventricular pacing and atrial-only pacing (r(2) = 0.78, P > .001).
  
  
  CONCLUSIONS
  Postoperative atrial synchronous biventricular and left ventricular pacing and atrial-only stimulation significantly improve systolic function relative to atrial synchronous right ventricular outflow tract pacing. If atrioventricular conduction is prolonged, atrial synchronous biventricular pacing is preferable to atrial-only pacing.
authors: Department of Cardiac and Thoracic Vascular Surgery, University of Lübeck, Lübeck, Germany.
authors: Thorsten
authors: T
authors: Hanke
authors: Martin
authors: M
authors: Misfeld
authors: Matthias
authors: M
authors: Heringlake
authors: Jan J
authors: JJ
authors: Schreuder
authors: Uwe K H
authors: UK
authors: Wiegand
authors: Frank
authors: F
authors: Eberhardt
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D011182:Postoperative Care; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy*