Effects of milrinone versus epinephrine on left ventricular relaxation after cardiopulmonary bypass following myocardial revascularization: assessment by color m-mode and tissue Doppler.
OBJECTIVE
The purpose of this study was to evaluate the left ventricular lusitropic effects of epinephrine versus milrinone after cardiopulmonary bypass.


METHODS
Prospective randomized study.


METHODS
Single institution, university teaching hospital.


METHODS
Adult patients undergoing coronary artery bypass grafting under cardiopulmonary bypass.


METHODS
After separation from cardiopulmonary bypass, patients were randomized to receive intravenous epinephrine by continuous infusion (0.03 microg/kg/min) or milrinone (50 microg/kg followed by 0.5 microg/kg/min). Transesophageal echocardiographic evaluation of left ventricular diastolic function, with emphasis on relaxation, was performed before and after bypass and after the administration of either epinephrine or milrinone.


RESULTS
Measurements included pulse-wave Doppler analysis of mitral inflow and pulmonary vein and left ventricular outflow tract velocities. Left ventricular inflow velocity of propagation measured with color M-mode and tissue Doppler assessment of early mitral annulus velocity were used to evaluate left ventricular relaxation. Values of velocity of propagation and mitral annulus velocity improved significantly after bypass, suggesting improved relaxation. The administration of either epinephrine or milrinone did not result in further improvement in left ventricular relaxation.


CONCLUSIONS
After cardiopulmonary bypass, left ventricular relaxation was significantly improved. Neither epinephrine nor milrinone exhibited favorable lusitropic effects after bypass.
Lobato
Emilio B
EB
Department of Anesthesiology, University of Florida College of Medicine and Veterans Affairs Medical Center, Gainesville, 32610, USA. Elobato@anest.ufl.edu
Willert
Jessica L
JL
Looke
Thomas D
TD
Thomas
Jennifer
J
Urdaneta
Felipe
F
D000368:Aged; D002315:Cardiopulmonary Bypass / Q000379:methods*; D002316:Cardiotonic Agents / Q000494:pharmacology; D018618:Echocardiography, Doppler, Color / Q000379:methods; D017548:Echocardiography, Transesophageal / Q000379:methods; D004837:Epinephrine / Q000494:pharmacology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008875:Middle Aged; D020105:Milrinone / Q000494:pharmacology*; D009204:Myocardial Revascularization / Q000379:methods*; D015588:Observer Variation; D011182:Postoperative Care / Q000379:methods; D011446:Prospective Studies; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D016277:Ventricular Function, Left / Q000187:drug effects*
D002316:Cardiotonic Agents; D014662:Vasoconstrictor Agents; D020105:Milrinone; D004837:Epinephrine