[Myocardium-protective effects of phosphocreatine in experimental ischemia-reperfusion]

The protective effects of exogenous phosphocreatine were evaluated in vitro on isolated perfused rat hearts during reperfusion of ischemic myocardium. The hearts were randomly allocated in 2 groups. In the first (n 6) phosphocreatine was added at a concentration of 10 mM. The latter was utilized as control (n 7). In both groups the results showed a slight decrease in the post-ischemic myocardial performance. Aortic systolic pressure and flow respectively decreased on reperfusion by 17% and 12.5% in the phosphocreatine group and by 25.6% and 35% in the control group. Coronary flow was reduced by 10% in the phosphocreatine and by 18% in the control group. No statistically relevant differences were reported within or between the groups. No changes in heart rate occurred in the same period in the phosphocreatine and in the control group. Myocardial enzyme release during reperfusion showed significant lower levels of CK and LDH in the phosphocreatine group compared to controls (p less than 0.001 after 65 min and p less than 0.025 after 75 min between the 2 groups). The occurrence of serious ventricular arrhythmias was considerably higher in controls with respect to the phosphocreatine group. The overall incidence of major rhythm disturbances was 66% in the phosphocreatine group and 100% in the control group. Irreversible ventricular fibrillation (57%) occurred only in control hearts. The present findings indicate that phosphocreatine exerts a protective effect during myocardial ischemia and reperfusion, especially by preventing serious ventricular arrhythmias and by reducing myocardial enzyme release.