Axford-Gatley R A, Wilson G J, Feindel C M
Department of Pathology, University of Toronto, Ontario, Canada.
J Thorac Cardiovasc Surg. 1990 Sep;100(3):400-9.
Although several studies have shown better myocardial preservation with blood-based than asanguineous cardioplegic solutions at myocardial temperatures above 15 degrees C, one might suspect that blood would become unsafe at lower temperatures because of increased oxygen-hemoglobin affinity and viscosity. We compared myocardial preservation in dogs subjected to 6 hours of aortic crossclamping and treated with modified Roe's asanguineous cardioplegic solution at 4 degrees C (group CA), blood cardioplegic solution at 4 degrees C (CB), or blood cardioplegic solution at 27 degrees C (WB, four dogs per group). Myocardial preservation was assessed by triphenyltetrazolium staining of whole hearts, and by analysis of ultrastructure and morphometric analysis of mitochondria in myocardial biopsies from three sites in each heart (left ventricle subepicardium and subendocardium and right ventricle). Tetrazolium staining showed no difference in preservation among the three treatment groups (no necrosis in any heart). For two of the three biopsy sites (left ventricular subepicardium and right ventricle), ultrastructural and morphometric analyses demonstrated signs of more severe subcellular injury in group CA than in CB (p = 0.013 to 0.004), whereas equivalent preservation with all treatments was observed in the left ventricular endocardial site. Functional recovery also appeared to be equivalent between treatments, to the extent that all dogs were successfully weaned from bypass after 20 minutes of reperfusion. We conclude that the safety and effectiveness of blood cardioplegia is not compromised by infusion at 4 degrees C compared with 27 degrees C and that myocardial preservation is not improved by using asanguineous cardioplegia instead of blood cardioplegia at 4 degrees C.
尽管有几项研究表明，在心肌温度高于15摄氏度时，含血心脏停搏液比无血心脏停搏液能更好地保护心肌，但有人可能会怀疑，在较低温度下，由于氧与血红蛋白的亲和力增加和粘度升高，血液会变得不安全。我们比较了犬在主动脉交叉阻断6小时后，分别用改良的 Roe 无血心脏停搏液在4摄氏度下处理（CA组）、含血心脏停搏液在4摄氏度下处理（CB组）或含血心脏停搏液在27摄氏度下处理（WB组，每组4只犬）时的心肌保护情况。通过对全心脏进行三苯基四氮唑染色，以及对每只心脏三个部位（左心室心外膜下和心内膜下以及右心室）的心肌活检组织中的线粒体进行超微结构分析和形态计量分析来评估心肌保护情况。四氮唑染色显示三个治疗组之间的保护情况没有差异（所有心脏均无坏死）。对于三个活检部位中的两个（左心室心外膜下和右心室），超微结构和形态计量分析表明，CA组的亚细胞损伤迹象比CB组更严重（p = 0.013至0.004），而在左心室心内膜部位观察到所有治疗的保护效果相当。在所有犬在再灌注20分钟后均成功脱离体外循环的程度上，各治疗组之间的功能恢复似乎也相当。我们得出结论，与27摄氏度相比，4摄氏度下输注含血心脏停搏液不会损害其安全性和有效性，并且在4摄氏度下使用无血心脏停搏液代替含血心脏停搏液并不能改善心肌保护。
