title: Cardiovascular effects of propofol in dogs with dilated cardiomyopathy.
abstract: BACKGROUND
  The authors tested the hypothesis that propofol improves left ventricular diastolic function in dogs with dilated cardiomyopathy by reducing left ventricular preload and afterload.
  
  
  METHODS
  Seven dogs were instrumented for left ventricular and aortic pressures, aortic blood flow, and subendocardial segment length. Left ventricular afterload and contractility were quantified with aortic input impedance and preload recruitable stroke work, respectively. Diastolic function was evaluated with a time constant of left ventricular relaxation (tau); segment-lengthening velocities and time-velocity integrals during early left ventricular filling (dL/dtE and TVI-E, respectively) and atrial systole (dL/dtA and TVI-A, respectively); and a regional chamber stiffness constant (K). Dogs were paced at 240 beats/min for 18 +/- 3 days, and hemodynamics were recorded in sinus rhythm in the conscious state. Anesthesia was induced with propofol (5 mg/kg) and maintained with propofol infusions at 25, 50, and 100 mg x kg-1 x h-1, and hemodynamics were recorded after 15 min of equilibration at each dose.
  
  
  RESULTS
  Propofol decreased mean arterial pressure, left ventricular end-diastolic pressure, and K but did not change heart rate. Propofol reduced total arterial resistance and increased total arterial compliance derived from aortic input impedance. Propofol also reduced preload recruitable stroke work. The lowest dose of propofol decreased tau. Propofol decreased dL/dtE and TVI-E and reduced the dL/dt-E/A and TVI-E/A ratios.
  
  
  CONCLUSIONS
  Propofol reduces left ventricular preload, afterload, and regional chamber stiffness, causes direct negative inotropic effects, and impairs early-diastolic left ventricular filling in dogs with dilated cardiomyopathy.
authors.affiliation: Department of Anesthesiology, Medical College of Wisconsin and the Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee 53226, USA. ambarnes@mcw.edu
authors.forename: P S
authors.initials: PS
authors.lastname: Pagel
authors.forename: D A
authors.initials: DA
authors.lastname: Hettrick
authors.forename: J R
authors.initials: JR
authors.lastname: Kersten
authors.forename: D
authors.initials: D
authors.lastname: Lowe
authors.forename: D C
authors.initials: DC
authors.lastname: Warltier
mesh_terms: D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects*; D010101:Oxygen Consumption / Q000187:drug effects; D015742:Propofol / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol