Studies on myocardial protection by cold fluorocarbon (made in China) cardioplegic solution: Experiment on isolated rabbit heart

Abstract

Success or failure of open heart surgery is closely related to the effect of myocardial protection, and at present there is no unanimity of opinion as to the ideal protecting method. In this paper we compared the effects of myocardial protection on isolated rabbit heart afforded by the cold (4°C) oxygen-carrying perfluorotripropylamine (FTPA) cardioplegic solution (group A) and those afforded by the cold (4°C) St. Thomas cardioplegic solution (group B). We studied lactate dehydrogenase (LDH) in the effluent fluid of coronary sinus and ultrastructure of myocardial cells. No statistically significant difference in LDH release activity was observed between group A and group B during heart arrest perfusion, but it was evidently higher in group B than in group A during rewarming at 5, 10, 30, 45 min. Ultrastructure destructive changes of myocardium went alongside with the increase of release of the enzyme. After 45 min of rewarming perfusion, group A hearts showed essentially normal ultrastructure, but those in group B showed evident swelling of mitochondria, vesiculation and fatty changes of cytoplasm, dissolution and fragmentation of myofibrils, etc. The experimental results indicate that FTPA cardioplegic solution offers better myocardial protection than does St. Thomas cardioplegic solution.

Keywords

myocardial protection / cardioplegia / extracorporeal circulation / perfluorocarbon / open heart surgery

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