Relative time-profiles for free radical trapping, coronary flow, enzyme leakage, arrhythmias, and function during myocardial reperfusion.

A new finding is the discrimination between vascular radical concentration and rate of myocardial radical formation to investigate the pathogenic role of free radicals for the heart. For that purpose, the perfusate radical concentration (U/ml) and the rate of myocardial radical formation (U/min) were determined (using the ESR spin trap technique), and were compared to functional recovery, cellular damage, and rhythm disturbances of the reperfusion-injured hearts. The vascular radical concentration (during the first 5 min of reflow) significantly correlated to coronary flow reduction (in the same period) and contractile failure (recovery after 30 min of reperfusion). A significant correlation was found between the time-courses of radical concentration and the incidence of arrhythmias. The myocardial formation rate of free radicals (during the first minutes of reperfusion) showed a significant correlation to the following total myocardial release of creatine kinase. The results support the hypothesis that free radicals in the vascular system of the heart may contribute to the functional deterioration of the post ischemic heart. Moreover, this study provides evidence that total radical formation in the heart muscle during the first minutes of reflow is involved in the induction of tissue injury during reperfusion that may lead to the subsequent loss of intracellular enzymes.