[Clinical appraisal of myocardial protection for coronary artery bypass grafting--efficacy of retrograde continuous cold blood cardioplegia].

Myocardial protection is one of the most important problems during coronary artery bypass grafting in patients with severe coronary artery disease. In this communication we have demonstrated retrograde continuous cold blood cardioplegia (RC-CBCP) in such cases with preferable results. In this study myocardial protection for CABG surgery was evaluated from the points of the myocardial distribution of cardioplegic solution, the changes of the value of myocardial enzyme, the recovery of cardiac function after unclamping of the aorta, and the results of operation [mortality and incidence of perioperative infarction (PMI)]. The effects of myocardial protections were compared among the following 4 groups: group-A (n = 38) where antegrade cardioplegia with 10 ml/min of CBCP was used; group-R (n = 52), retrograde cardioplegia with 10 ml/min of CBCP; group-Rm (n = 59), retrograde cardioplegia with 7-8 ml/100 g LVMW (left ventricular mass weight)/min of CBCP; group-Rmt (n = 65), RC-CBCP with terminal warm blood cardioplegia (TWB). Judging from myocardial temperature measured at the end of initial cardioplegic infusion, the myocardial distribution of cardioplegic solution in group-R was significantly favorable even in the distal area of severe coronary artery stenotic lesions exceeding 90% compared with group-A. The recovery of cardiac function assessed from the incidence of occurrence of spontaneous beating and the dose of cathecholamine at the weaning of cardiopulmonary bypass were most excellent in group-Rmt among the 4 groups. There was no significant difference in postoperative peak CK-MB and LDH-1 isoenzyme levels among the 4 groups.(ABSTRACT TRUNCATED AT 250 WORDS)