The Optimum Temperature of the Retrograde Continuous Blood Cardioplegia in Coronary Artery Bypass Grafting / 日本心臓血管外科学会雑誌

ABSTRACT

Myocardial oxidative stress during retrograde continuous blood cardioplegia (RCBC) was evaluated in 35 patients undergoing elective aortocoronary bypass surgery. The patients were divided into three groups: Group C (<i>n</i>=12) received cold (20°C) RCBC, Group T (<i>n</i>=11) received tepid (30°C) RCBC, and Group W (<i>n</i>=12) received warm (36°C) RCBC. Myocardial oxidative stress was assessed by measuring the release of oxidized glutathione (GSSG), malondialdehyde (MDA), and myeloperoxidase (MPO) in the coronary sinus plasma before aortic clamping, at 1, 5, and 10min after unclamping. Myocardial oxygen uptake and lactate release were assessed at the same times. Both the hemodynamic recovery and the creatine kinase MB (CKMB) activity were measured perioperatively until 24h after unclamping. In Group C, a significant coronary sinus release of GSSG was found in the early reperfusion period in comparison to Groups T and W. However, the peak CK-MB activity was significantly lower in Group T than in Group W. No significant difference in the release of MDA or MPO was noted in the three groups. The recovery of oxygen uptake after unclamping was rapid in Group T. The recovery in the left and right ventricular functions and the myocardial lactate release were similar in the three groups. In conclusion, tepid RCBC is considered to protect the myocardium from ischemia-reperfusion injury better than cold or warm blood cardioplegia under retrograde continuous perfusion.