The purpose of this study was to evaluate the effects of propofol-fentanyl anesthesia in comparison with fentanyl alone on the functional recovery of postischemic reperfused myocardium and on the incidence of ischemia-reperfusion arrhythmia in an open-chest canine model.

Dogs were subjected to 15 minutes of left anterior descending coronary artery (LAD) occlusion followed by 3 hour of reperfusion during fentanyl (n=12) or propofol plus fentanyl (n=11) anesthesia. Regional myocardial contractility was evaluated using systolic shortening (%SS), the preload recruitable stroke work slope (Mw), intramyocardial pressure (IMPs), and regional stroke work area (RSWA).

Dogs anesthetized with propofol-fentanyl had a significantly lower regional (%SS, Mw, IMPs, and RSWA) and global myocardial contractility (cardiac index, mean aortic pressure and left ventricular dP/dt) than fentanyl anesthetized dogs during pre-occlusion baseline. LAD occlusion produced a significant reduction in the regional contractile functions (%SS, Mw, IMPs, and RSWA) in both groups. During reperfusion, gradual return of the regional contractile functions (%SS, Mw, IMPs, RSWA) toward their respective baselines were observed without any differences between the groups. However, ventricular fibrillation associated with LAD occlusion was lower in the propofol-fentanyl group than in the fentanyl group (zero vs 33%, p<0.05).

Propofol supplementation over moderate-dose fentanyl reduces reperfusion arrhythmia during coronary occlusion and subsequent reperfusion but does not improve functional recovery of post-ischemic, reperfused myocardium compared with high-dose fentanyl anesthesia in dogs.