title: Cardiopulmonary bypass impairs left ventricular function determined by conductance catheter measurement.
abstract: OBJECTIVE
  Postoperative cardiac depression is attributed to ischemia and the effects of cardiopulmonary bypass (CPB). To evaluate the effect of CPB alone on postoperative left ventricular (LV) dysfunction, we used a conductance catheter to determine the LV performance by pressure-volume relation before and after CPB.
  
  
  METHODS
  Twenty-two 3-week-old piglets underwent sternotomy and normothermic CPB for one hour. A conductance catheter was placed in the LV cavity. End-systolic pressure-volume relationships (ESPVR), left ventricular end-diastolic pressure (LVEDP) and systemic vascular resistance (SVR) were measured under steady-state conditions before and 15 min after weaning from CPB in group A (n = 11). Group B included 11 piglets without CPB and served as control.
  
  
  RESULTS
  There was no difference between groups before initiating CPB. As an indication of depressed LV function, the ESPVR slope (mmHg/ml) was significantly lower in group A after weaning from CPB than in group B (1.69 +/- 0.5 vs. 1.86 +/- 0.55; p = 0.008). In group A, peak dP/dt (max index) (mmHg/s/m (2)) decreased markedly (1596 +/- 339 vs. 2045 +/- 206; p = 0.03), while LVEDP (mmHg) was significantly increased (11.7 +/- 2.6 vs. 5.4 +/- 0.9; p < 0.0001). In addition, SVR (index) (dyn x s x cm (-5)/m (2)) in group A was significantly lower (1407 +/- 176 vs. 1677 +/- 313; p < 0.0001) than in group B.
  
  
  CONCLUSIONS
  Using the very sensitive conductance catheter technique in a pig model, we could show that CPB leads to a significant depression of LV contractility and elastance even without ischemic arrest.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Johann Wofgang Goethe University, Frankfurt, Germany. T.Aybek@em.uni-frankfurt.de
authors.forename: T
authors.initials: T
authors.lastname: Aybek
authors.forename: M F
authors.initials: MF
authors.lastname: Kahn
authors.forename: S
authors.initials: S
authors.lastname: Dogan
authors.forename: U
authors.initials: U
authors.lastname: Abdel-Rahman
authors.forename: S
authors.initials: S
authors.lastname: Mierdl
authors.forename: P
authors.initials: P
authors.lastname: Kessler
authors.forename: G
authors.initials: G
authors.lastname: Wimmer-Greinecker
authors.forename: A
authors.initials: A
authors.lastname: Moritz
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization; D002315:Cardiopulmonary Bypass; D004548:Elasticity; D006439:Hemodynamics; D023421:Models, Animal; D009200:Myocardial Contraction; D011184:Postoperative Period; D013552:Swine; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology*; D017725:Ventricular Pressure