Controlled versus hyperemic flow during reperfusion of jeopardized ischemic myocardium

Controlled versus uncontrolled reperfusion of ischemic myocardium after experimental coronary artery occlusion was studied to determine the effect on regional ventricular wall motion and associated biochemical alterations. Fourteen pigs underwent coronary artery occlusion for 1 hour followed by 2 hours of reperfusion. In seven animals uncontrolled reperfusion was achieved by complete release of the arterial occlusion resulting in hyperemic flow. In seven other animals coronary flow during reperfusion was controlled at baseline levels eliminating hyperemic flow. Our results show that controlled reperfusion lessens end-diastolic wall thickness, reduces myocardial calcium deposition, increases the rate of mitochondrial oxidative phosphorylation, and preserves cellular high-energy phosphate stores in the ischemic-reperfused myocardium when compared to the uncontrolled reperfusion state. These data suggest that the magnitude of flow at an early stage of reperfusion is one of the important determinants in the outcome of ischemic myocardium.