Heng M K, Singh B N, Norris R M, John M B, Elliot R
J Clin Invest. 1976 Dec;58(6):1317-26. doi: 10.1172/JCI108587.
The relationship between early and late epicardial electrocardiographic changes as well as those in regional myocardial blood flow (MBF) and the severity of myocardial damage was determined in 12 anesthetized dogs with left anterior descending coronary artery ligation. Radioactive microspheres (15 mum) were used to measure regional MBF at 15 min (early) and 24 h (late) after coronary occlusion. Severity of myocardial damage was assessed by the extent of myocardial creatine phosphokinase depletion 24 h after coronary ligation. There was a close linear correlation between myocardial creatine phosphokinase activity and regional MBF both early (r=0.93, 2P less than 0.001) and late (r=0.88, 2P less than 0.001). An inverse but less precise relationship existed between acute epicardial ST-segment elevation and early (r=-0.41, 2P less than 0.001), or late (r=0.35, 2P less than 0.05) regional MBF. Similarly, a weak correlation was found between myocardial creatine phosphokinase (IU/mg protein) at 24 h and early epicardial ST (millivolt) elevation (r=-0.36, 2P less than 0.02). In the center zones of the infarct with MBF 1/10 of normal, about 35% of the areas with normal QRS width had no epicardial ST-segment elevation 15 min after coronary occlusion. About 44% of the areas which developed pathological Q-waves in the electrocardiogram at 24 h had no ST elevation 15 min after coronary ligation. Late evolution of abnormal Q-waves occurred almost invariably in areas in which the early MBF was reduced to less than 50% of normal and in areas which subsequently had myocardial creatine phosphokinase levels reduced to less than 60% of normal. After coronary occlusion, the severity of the ultimate myocardial damage, which was directly proportional to the degree of reduction in MBF, was therefore not reliably predicted by the early epicardial ST-segment elevation. The data obtained in these studies suggest the need for caution in the use of acute ST-segment elevation as a predictive index of the extent or severity of myocardial ischemic damage.
在12只麻醉的左冠状动脉前降支结扎犬中，确定了早期和晚期心外膜心电图变化以及局部心肌血流量（MBF）变化与心肌损伤严重程度之间的关系。使用放射性微球（15μm）在冠状动脉闭塞后15分钟（早期）和24小时（晚期）测量局部MBF。通过冠状动脉结扎后24小时心肌肌酸磷酸激酶消耗程度评估心肌损伤的严重程度。心肌肌酸磷酸激酶活性与局部MBF在早期（r = 0.93，2P＜0.001）和晚期（r = 0.88，2P＜0.001）均呈密切线性相关。急性心外膜ST段抬高与早期（r = -0.41，2P＜0.001）或晚期（r = 0.35，2P＜0.05）局部MBF呈负相关，但相关性较弱。同样，在24小时时心肌肌酸磷酸激酶（IU/mg蛋白）与早期心外膜ST（毫伏）抬高之间发现弱相关性（r = -0.36，2P＜0.02）。在梗死中心区域，MBF为正常的1/10，在冠状动脉闭塞后15分钟，约35% QRS波宽度正常的区域无心外膜ST段抬高。在24小时心电图出现病理性Q波的区域中，约44%在冠状动脉结扎后15分钟无ST段抬高。异常Q波的晚期演变几乎总是发生在早期MBF降至正常的50%以下的区域以及随后心肌肌酸磷酸激酶水平降至正常的60%以下的区域。冠状动脉闭塞后，最终心肌损伤的严重程度与MBF降低程度成正比，因此早期心外膜ST段抬高不能可靠地预测其严重程度。这些研究中获得的数据表明，在将急性ST段抬高用作心肌缺血损伤范围或严重程度的预测指标时需谨慎。
