Effects of dobutamine and enoximone on transmitral and pulmonary venous flow characteristics in patients with left ventricular dysfunction after coronary artery bypass grafting.
OBJECTIVE
To assess the effects of dobutamine and enoximone on transmitral (TMF) and pulmonary venous flow (PVF) characteristics.


METHODS
Prospective and randomized.


METHODS
A university hospital intensive care unit.


METHODS
Thirty patients with moderate left ventricular dysfunction after coronary artery bypass grafting (CABG).


METHODS
Patients received either dobutamine, 10 micrograms/kg/min, or enoximone, 20 micrograms/kg/min, for the treatment of a low cardiac index (CI) (< 2.2 L/min/m2).


RESULTS
Both drugs significantly (p < 0.05) increased CI from 1.91 +/- 0.17 (dobutamine) and 1.97 +/- 0.17 (enoximone) at baseline to 2.86 +/- 0.70 and 2.84 +/- 0.39 L/min/m2, respectively. Compared with the enoximone (enox)-treated group, the administration of dobutamine (dob) resulted in significantly (p < 0.05) greater increases in mean arterial pressure (dob: 18 +/- 9% v enox: -2 +/- 7%), heart rate (dob: 24 +/- 13% v enox: 3 +/- 5%) and pulmonary artery pressure (dob: 5 +/- 10% v enox: -4 +/- 9%). In contrast, the increase in stroke volume index was significantly less in the dobutamine-treated group (dob: 22 +/- 27% v enox: 41 +/- 21%). The TMF indices, peak E, and peak A wave increased significantly (p < 0.05) after both dobutamine (baseline: 37.3 +/- 6.7 and 41.1 +/- 9.3; max dose: 42.4 +/- 4.3 and 49.0 +/- 10.2 cm/s) and enoximone (baseline: 36.2 +/- 7.5 and 44.2 +/- 10.9; max dose: 40.5 +/- 5.0 and 49.4 +/- 12.1 cm/s) without significantly altering the E/A ratio. Only dobutamine significantly (p < 0.05) decreased isovolumic relaxation time from 109 +/- 24 to 94 +/- 21 ms. There was no significant change in isovolumic relaxation time between the dobutamine (-12% +/- 17%)- and the enoximone (-4% +/- 21%)- treated group. PVF recordings demonstrated a significant increase in time velocity integrals of the S wave with both dobutamine (12.2 +/- 3.1 v 13.7 +/- 3.2 cm) and enoximone (11.0 +/- 3.0 v 12.2 +/- 3.2 cm). No changes in the systolic fraction of the PVF were noted.


CONCLUSIONS
There were no major differences in parameters reflecting diastolic function between the dobutamine- and the enoximone-treated groups.
Vroom
M B
MB
Department of Anesthesia, Academic Medical Center, Amsterdam, The Netherlands.
van Wezel
H B
HB
vd Brink
R B
RB
vd Lee
R
R
Eijsman
L
L
Visser
C A
CA
van Zwieten
P A
PA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002316:Cardiotonic Agents / Q000494:pharmacology*; D001026:Coronary Artery Bypass; D003971:Diastole / Q000187:drug effects; D004280:Dobutamine / Q000494:pharmacology*; D017335:Enoximone / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000187:drug effects / Q000503:physiopathology; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*
D002316:Cardiotonic Agents; D004280:Dobutamine; D017335:Enoximone