Hashimoto K, Corday E, Lang T W, Rubins S, Meerbaum S, Osher J, Farcot J C, Davidson R M
Am J Cardiol. 1976 Mar 31;37(4):493-500. doi: 10.1016/0002-9149(76)90387-8.
A method is described for measuring intracoronary S-T segment elevations in the closed chest, a technique that appears to provide more reliable measurements of myocardial ischemia. Electrodes were inserted through intracoronary balloon catheters that were placed within a coronary artery and its adjoining vein both proximal and at several points distal to a coronary occlusion. Intracoronary arterial and adjacent venous electrocardiograms produced equivalent tracings. The intracoronary S-T segment elevations after coronary occlusion resembled those recorded from the epicardial surface but were free of artifacts noted in open chest studies. Study of progressive alterations of the intracoronary S-T segment after proximal occlusion of the left anterior descending coronary artery in 18 closed chest dogs revealed a peak segment elevation of 3.2 +/- 0.6 mv within 5 minutes, followed within 2 to 3 hours by spontaneous reduction by more than 40% of the S-T elevation over the occluded zone. In 44% of these animals, the S-T elevation decreased spontaneously to less than 1 mv, and in 22% it decreased to the preocclusion control level within 2 hours of occlusion. This spontaneous decrease in S-T elevation was frequently followed by a secondary increase and then S-T segment fluctuations. Reperfusion of the left anterior descending coronary artery after 30 to 60 minutes of occlusion generally led to a prompt reduction in S-T elevation. In some cases S-T elevations persisted up to 14 hours of occlusion, were reduced after reperfusion and exhibited a renewed pronounced increase after subsequent reocclusion of the left anterior descending coronary artery. During the 1st hour after occlusion, the early S-T segment elevation followed by spontaneous reduction reduction generally corresponded temporally with the derangements in myocardial lactate extraction and potassium loss. However, after 1 hour of occlusion no clear-cut correlation could be established between S-T fluctuations and changes in hemodynamic or myocardial metabolic measurements. We conclude that the new closed chest intracoronary electrocardiographic S-T technique might be of use for monitoring the early ischemic myocardial derangements and to assess benefits or drawbacks of treatment in both the experimental animal and man. Correspondence of S-T segment elevation with lactate and potassium alterations in the coronary-occluded region in the 1st hour after occlusion indicates that S-T segment elevation might represent an index of early myocardial ischemia. The spontaneous S-T changes that follow coronary occlusion must be taken into consideration when investigators utilize S-T segment modification as a sign of effectiveness of treatment.
本文描述了一种用于在闭合胸腔内测量冠状动脉S-T段抬高的方法，该技术似乎能提供更可靠的心肌缺血测量结果。电极通过冠状动脉球囊导管插入，导管放置在冠状动脉及其相邻静脉内，位于冠状动脉闭塞近端及远端的几个点处。冠状动脉内动脉和相邻静脉心电图产生了等效的描记图。冠状动脉闭塞后的冠状动脉内S-T段抬高类似于心外膜表面记录的情况，但没有开胸研究中出现的伪迹。对18只闭合胸腔犬左前降支冠状动脉近端闭塞后冠状动脉内S-T段的进行性改变研究显示，5分钟内S-T段抬高峰值为3.2±0.6毫伏，随后在2至3小时内，闭塞区S-T抬高自发降低超过40%。在这些动物中，44%的动物S-T抬高自发降低至小于1毫伏，22%的动物在闭塞后2小时内降低至闭塞前对照水平。S-T抬高的这种自发降低之后常常接着是二次升高，然后是S-T段波动。闭塞30至60分钟后左前降支冠状动脉再灌注通常导致S-T抬高迅速降低。在某些情况下，S-T抬高持续至闭塞后14小时，再灌注后降低，并且在左前降支冠状动脉随后再次闭塞后出现再次明显升高。在闭塞后的第1小时内，早期S-T段抬高随后自发降低通常在时间上与心肌乳酸摄取和钾丢失的紊乱相对应。然而，闭塞1小时后，S-T波动与血流动力学或心肌代谢测量变化之间无法建立明确的相关性。我们得出结论，新的闭合胸腔冠状动脉内心电图S-T技术可能用于监测早期缺血性心肌紊乱，并评估实验动物和人类治疗的利弊。闭塞后第1小时冠状动脉闭塞区域内S-T段抬高与乳酸和钾改变的对应关系表明，S-T段抬高可能代表早期心肌缺血的一个指标。当研究人员将S-T段改变用作治疗有效性的标志时，必须考虑冠状动脉闭塞后S-T段的自发变化。
