Rainio P, Kaukoranta P K, Sormunen R, Juvonen T, Peuhkurinen K J
Department of Anaesthesiology, Oulu University Hospital, Finland.
Scand Cardiovasc J. 1998;32(6):353-9. doi: 10.1080/14017439850139807.
Uniformity of myocardial protection during retrograde blood cardioplegia is still a controversial area. We conducted a study on electron microscopic changes in the myocardium during mild hypothermic retrograde cardioplegia (31-32 degrees C) in 12 patients undergoing coronary artery bypass grafting. Biopsies for electron microscopy were taken from the right and left ventricular myocardium before and at the end of aortic cross-clamping and after 15 min reperfusion. The intercellular junctions, intracellular and extracellular oedema, mitochondria, capillaries, nuclei and myofibrils were analysed separately in each specimen, using a semiquantative method with scoring from 0 (unchanged) to 3 (severe changes), and the total scores were correlated with the severity of right and left coronary artery disease and with ischaemia time during aortic cross-clamping. Mild to moderate ultrastructural changes occurred in the myocardium during the cardiopolegia, most typically myofibrillar injury and oedema. These changes increased during aortic cross-clamping and reperfusion, especially in the right ventricle. The total ultrastructural score for the right ventricle correlated negatively with the severity of right coronary artery disease at the end of cross-clamping. No such correlation was found in the left ventricle. Apart from one case of perioperative myocardial infarction, the clinical outcome was unproblematic. Myocardial structure thus was by and large well preserved during mild hypothermic retrograde blood cardioplegia, with the right ventricle seemingly somewhat less protected than the left.
逆行性血液停搏期间心肌保护的均匀性仍是一个存在争议的领域。我们对12例接受冠状动脉搭桥术的患者在轻度低温逆行性停搏（31 - 32摄氏度）期间心肌的电子显微镜变化进行了研究。在主动脉阻断前、主动脉阻断结束时以及再灌注15分钟后，从右心室和左心室心肌获取用于电子显微镜检查的活检组织。对每个标本中的细胞间连接、细胞内和细胞外水肿、线粒体、毛细血管、细胞核和肌原纤维分别进行分析，采用半定量方法，评分从0（无变化）到3（严重变化），总评分与左右冠状动脉疾病的严重程度以及主动脉阻断期间的缺血时间相关。在心脏停搏期间心肌出现轻度至中度超微结构变化，最典型的是肌原纤维损伤和水肿。这些变化在主动脉阻断和再灌注期间增加，尤其是在右心室。右心室的总超微结构评分与主动脉阻断结束时右冠状动脉疾病的严重程度呈负相关。在左心室未发现这种相关性。除1例围手术期心肌梗死外，临床结果无问题。因此，在轻度低温逆行性血液停搏期间心肌结构总体上保存良好，右心室似乎比左心室受到的保护稍少。
