Hemodynamic effects of alfentanil in verapamil-treated dogs

The hemodynamic effects of alfentanil were investigated in six dogs receiving verapamil 0.5 mg X kg-1 and six dogs receiving saline in equal volume. Basic measurements were done after 30 min and the dogs were then given alfentanil 160 micrograms X kg-1 with measurements at 5, 15, and 30 min. Significant increases in central venous pressure (CVP), mean pulmonary arterial pressure and pulmonary wedge pressure (PWP) were found 30 min after verapamil. After verapamil-alfentanil, increases were seen in CVP and PWP at 5 and 15 min and in PWP at 30 min. Mean arterial pressure and cardiac index were unchanged, while a decrease in heart rate was fully compensated by an increase in stroke volume. Indices of contractility were unchanged. All values were within the limits of normal hemodynamic function. We conclude that high-dose alfentanil has no adverse effects on hemodynamic parameters during calcium blockade.