[Comparison of the hemodynamic effect of enoximone and dopamine in patients after coronary bypass operation].

The efficacy of acute hemodynamic support with intravenous enoximone (n = 10), (2 x bolus 0.5 mg/kg, infusion 5.0 mcg/kg/min), dopamine (n = 10), (3-4.0 mcg/kg/min) over a 18-h period was investigated in patients to be weaned off cardio-pulmonary bypass (CPB) (placebo-controlled trial). Under steady-state conditions enoximone produced a substantial increase in cardiac index (20.6 +/- 1.7%), but no change in heart rate. The improvement in cardiac index with time until constant values were reached (6 h) was not directly paralleled by the plasma concentration of enoximone. Pharmacodynamically relevant concentrations were already present after 1 h of infusion (480 +/- 68 ng/ml) and were comparable with the value determined after 6 h (442 +/- 31 ng/ml). After 18 h of infusion, plasma concentration had reached 742 +/- 47 ng/ml without a further improvement in cardiac function. The augmentation of stroke volume index (23.3 +/- 2.5%) occurred concomitant with a decrease in systemic vascular resistance (-23.1 +/- 0.6%), obviously due to a decrease in diastolic arterial pressure (-12.0 +/- 3.8%). The pulmonary capillary wedge pressure remained unaffected, and there was only a slight decrease in pulmonary vascular resistance (-9.3 +/- 3.2%). During enoximone, as well as dopamine infusion, an increase (10 +/- 3.1 and 9 +/- 1.8%) in right atrial pressure was observed in contrast to the untreated control group. This is contradictory to the described drugs effect in patients suffering from congestive heart failure. In a concentration usually not causing cardioacceleration, dopamine was of minor hemodynamic support in the post-CPB period.(ABSTRACT TRUNCATED AT 250 WORDS)