[Experimental study on myocardial preservation by perfluorochemical "comparison of myocardial preservation effect...

The effect of myocardial preservation with perfluorochemical as cardioplegic solution was studied with isolated canine hearts which was compared between intermittent coronary perfusion and continuous coronary perfusion. Intermittent perfusion group (group I) was infused every 30 minutes during 5 hours ischemia with oxygenated perfluorochemical at the amount of 10 ml/kg. Continuous perfusion group (group II) was infused continuously at the amount of 10 ml/kg/30 minutes. After 5 hours of ischemic time, total perfusion volume of both group were same 100 ml/kg. The comparison of myocardial preservation effect between group I and group II was examined with biochemical study, hemodynamic study and histological study. As a result, biochemical study such as GOT, CPK, and Lactate showed higher in group II than in group I, and value of catecholamine and adenylate levels in myocardial tissue showed higher in group I than in group II. In hemodynamic study, LVSW and LVEDP showed excellent value in group I, but never showed adequate function in group II at late working phase. On the other hand, LVmax dp/dt was recovered excellently in group I but in group II was not recovered at early working phase. In histological findings with electronic microscopy, there were some limited ischemic lesion in group II, which was suggested disturbance of micro circulation. It may be attributable to low perfusion pressure of continuous perfusion method. Finally, with regard to SOD (Super oxide dismutase) consumption, group I took higher than group II, and also oxygen consumption. It shows that in group I there is an effective activity of aerobic metabolism during ischemia, which explain not only the improved functional recovery but also generation of free radical, caused by super oxide etc. It is concluded from these results that intermittent perfusion has provided excellent preservation against myocardial ischemia, and also has possibility of danger to set up reperfusion injury.