Treating metabolic impairment and myocardial stunning with phosphodiesterase inhibitor type III, milrinone, administered prior to coronary artery occlusion in the presence of calcium channel blockade in pigs.

Abstract

This study examined milrinone effects on ischaemic myocardial metabolism and function with calcium blockade. We studied 15 pigs in 3 groups: group C received no drugs; group D received diltiazem 5 mg bolus followed by infusion; group D+M received diltiazem and milrinone (50microg/Kg). The left anterior descending (LAD) artery was then occluded for 15 minutes. Left ventricular (LV) function data obtained included rate, pressures, output, Emax, and dP/dT. Blood lactate was obtained from the LAD and circumflex vessels at baseline, end of occlusion, early (15 min) and late (1 hour) reperfusion. In group D+M, less depression of LV function occurred during ischaemia and early reperfusion. Lactate extraction in the LAD region was less negative in D+M group than in the group without milrinone during ischaemia and late reperfusion. We conclude the preemptive administration of milrinone prior to ischaemia added to calcium blockade improved myocardialfunction and ischaemic metabolic effects.