Konta T, Ikeda K, Yamaki M, Nakamura K, Honma K, Kubota I, Yasui S
First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Circulation. 1990 Dec;82(6):2185-9. doi: 10.1161/01.cir.82.6.2185.
With the use of epicardial mapping, we investigated the electrical alternans of the ST segment during acute myocardial ischemia and studied the difference in ST alternans between dogs with resultant ventricular fibrillation and those without it. During the 7-minute occlusion of the left anterior descending coronary artery below its first diagonal branch, 60 epicardial unipolar electrograms were recorded simultaneously at 1-minute intervals by a computerized mapping system. ST alternans was found in the eight dogs we observed. The amplitude of ST alternans (difference in the ST segment elevation of two consecutive electrograms) was greater in dogs with ventricular fibrillation (n = 4) than in those without it (n = 4) (3.92 +/- 1.24 versus 0.58 +/- 0.49 mV, p less than 0.05). Three of the four dogs with ventricular fibrillation demonstrated discordant ST alternans (i.e., adjacent leads were out of phase). Results from the present study indicate that an increased amplitude and discordance of ST alternans during acute myocardial ischemia are related to ventricular fibrillation and act as indicators of time and spatial unevenness of ventricular repolarization.
通过心外膜标测，我们研究了急性心肌缺血期间ST段的电交替现象，并探讨了发生心室颤动的犬与未发生心室颤动的犬之间ST段交替的差异。在左前降支冠状动脉第一对角支下方进行7分钟的闭塞期间，通过计算机标测系统以1分钟的间隔同时记录60个心外膜单极电图。在我们观察的8只犬中发现了ST段交替现象。发生心室颤动的犬（n = 4）的ST段交替幅度（连续两个电图的ST段抬高差异）大于未发生心室颤动的犬（n = 4）（3.92±1.24对0.58±0.49 mV，p<0.05）。4只发生心室颤动的犬中有3只表现出不一致的ST段交替（即相邻导联不同步）。本研究结果表明，急性心肌缺血期间ST段交替幅度的增加和不一致与心室颤动有关，并且可作为心室复极时间和空间不均匀性的指标。
