[Retrograde continuous cold blood cardioplegia via coronary sinus]

Though the retrograde continuous cold blood cardioplegia (RC-CBCP) is a useful method of myocardial protection for more complicated cardiac surgery, the most important problem is whether the right ventricle is satisfactorily protected or not. In the present study 60 patients with valvular heart disease given RC-CBCP were compared with 30 patients given antegrade continuous cold blood cardioplegia. Judging from myocardial temperature measured in the right ventricular wall, the ventricular septum and the left ventricular wall at the end of initial cardioplegic infusion, myocardial distribution of cardioplegic solution in the RC-CBCP group was as favorable as in the antegrade group. Injury to mitochondria in the right ventricular myocardium observed in the biopsy specimen taken just prior to aortic unclamping was usually trifling in the RC-CBCP group, and was not different significantly from that in the antegrade group. Cold blood cardioplegia dose perfused per left ventricular mass weight (LVMW) had significant correlation with injury to mitochondria, and the dose of more than 5ml/100gLVMW/min seemed to be preferable. There was no hospital death in all patients. Peak CK-MB after unclamping was less in the RC-CBCP group than the antegrade group. In conclusion, RC-CBCP is a safe and effective means of myocardial protection for both right and left ventricles.