Kaukoranta P K, Lepojärvi M V, Kiviluoma K T, Ylitalo K V, Peuhkurinen K J
Department of Anesthesiology, Oulu University Hospital, Finland.
Ann Thorac Surg. 1998 Sep;66(3):755-61. doi: 10.1016/s0003-4975(98)00459-7.
It has been suggested that the right ventricular myocardium is suboptimally protected during retrograde blood cardioplegia.
Twenty patients undergoing an elective coronary bypass procedure were randomized to receive antegrade or retrograde mild hypothermic blood cardioplegia. Transventricular differences in oxygen extraction, lactate production, and pH were monitored during aortic cross-clamping, and myocardial biopsy specimens were taken from both ventricles before cannulation and 15 minutes after aortic declamping for analysis of adenine nucleotides and their breakdown products. The extent of myocardial injury was estimated by monitoring postoperative leakage of troponin T and the MB isoenzyme of creatine kinase. Hemodynamic recovery and postoperative complications were noted.
The preoperative characteristics of the two groups were similar. Oxygen extraction and lactate production in the right ventricular myocardium were higher in the retrograde group. In this group, the right ventricle also extracted more oxygen and produced more lactate and acid than did the left ventricle. Tissue levels of adenine nucleotides tended to decrease in both ventricles during operation, with no differences between them. The level of adenosine catabolites did increase somewhat in the right ventricular myocardium of the retrograde cardioplegia group after aortic declamping. There was a tendency for more prominent efflux of troponin T and the MB isoenzyme of creatine kinase in the retrograde group. Nevertheless, the postoperative course was uneventful in both groups.
Retrograde mild hypothermic blood cardioplegia leads to metabolic changes compatible with right ventricular ischemia. Nevertheless, tissue levels of high-energy phosphates are well preserved, and the postoperative course seems to be unproblematic. Care should be taken when retrograde normothermic blood cardioplegia is provided for patients with right ventricular hypertrophy, poor right ventricular function, or severe preoperative myocardial ischemia.
有人提出，在逆行血液停搏期间，右心室心肌未得到最佳保护。
20例行择期冠状动脉搭桥手术的患者被随机分为接受顺行或逆行轻度低温血液停搏组。在主动脉阻断期间监测心室间氧摄取、乳酸生成和pH值的差异，并在插管前和主动脉开放后15分钟从两个心室获取心肌活检标本，分析腺嘌呤核苷酸及其分解产物。通过监测术后肌钙蛋白T和肌酸激酶MB同工酶的漏出来评估心肌损伤程度。记录血流动力学恢复情况和术后并发症。
两组患者术前特征相似。逆行组右心室心肌的氧摄取和乳酸生成较高。在该组中，右心室比左心室摄取更多的氧、产生更多的乳酸和酸。手术期间两个心室的腺嘌呤核苷酸组织水平均有下降趋势，两者之间无差异。在逆行停搏组中，主动脉开放后右心室心肌中腺苷分解产物的水平确实有所增加。逆行组中肌钙蛋白T和肌酸激酶MB同工酶的流出有更明显的趋势。然而，两组术后过程均顺利。
逆行轻度低温血液停搏导致与右心室缺血相符的代谢变化。然而，高能磷酸盐的组织水平保存良好，术后过程似乎没有问题。对于右心室肥厚、右心室功能差或术前严重心肌缺血的患者，在进行逆行常温血液停搏时应谨慎。
