Li C Y, Jia L Z, Wang L
Department of Biophysics, School of Physics, Nankai University, Tianjin, People's Republic of China, and.
Exp Clin Cardiol. 2001 Winter;6(4):179-82.
To study the value of epicardial QT interval dispersion in predicting ischemia-induced heterogeneity of ventricular repolarization.
Ischemia was produced by total occlusion of the obtuse branch of the circumflex coronary artery in seven open-chest sheep. A 64-channel electrocardiogram (ECG) was acquired from the epicardium before and after coronary artery occlusion. Wavelet transformation was used to determine the characteristic points of the epicardial ECGs, and to measure the QT interval and activation-recovery interval (ARI) and their dispersions.
The average QT interval and ARI from the epicardial ECG were not changed by acute myocardial ischemia (P=0.07 and P=0.13, respectively). QT dispersion remained unchanged during ischemia (P=0.17), whereas ARI dispersion was significantly increased by acute ischemia (59.9+/-24.0 ms versus 126.3+/-32.1 ms, P<0.001).
These findings indicate that epicardial QT dispersion is less sensitive than ARI dispersion in estimating repolarization heterogeneity induced by acute myocardial ischemia.
研究心外膜QT间期离散度在预测缺血诱导的心室复极异质性中的价值。
通过完全闭塞7只开胸绵羊的冠状动脉旋支钝缘支制造缺血模型。在冠状动脉闭塞前后从心外膜获取64通道心电图（ECG）。采用小波变换确定心外膜心电图的特征点，并测量QT间期和激活-恢复间期（ARI）及其离散度。
急性心肌缺血未改变心外膜心电图的平均QT间期和ARI（分别为P = 0.07和P = 0.13）。缺血期间QT离散度保持不变（P = 0.17），而急性缺血使ARI离散度显著增加（59.9±24.0毫秒对126.3±32.1毫秒，P<0.001）。
这些发现表明，在心外膜评估急性心肌缺血诱导的复极异质性方面，QT离散度比ARI离散度敏感性更低。
