Kim E M, Katoh T
1st Dept. of Int. Med., Nippon Medical School.
Nihon Rinsho. 1995 Feb;53(2):384-9.
Non invasive recording of late potential (LP) by signal-averaged electrocardiogram (SAE) is useful in predicting ventricular tachycardia (VT) especially in patients with myocardial infarction (MI). However, the rate of positive LP is not high enough to get clinical significance in anterior or anteroseptal MI, since the LP has been masked by QRS complex. The purpose of the present study is, to evaluate the clinical significance of the initial delay in patients with MI. 80 patients of MI were divided into four groups: AS (anteroseptal, n = 18, including 6 VT), A: (anterior, n = 22.7 VT), I: (inferior, n = 28.9 VT) and P: (posterior, n = 12, no VT). 20 non-MI patients were used for normal control (N). NEC7T18 was used to record SAE and each 5 msec integral values of filtered QRS complex from the initial upstroke to 60 msec point was measured. Integral values of AS and A were significantly lower than that of group I, P, and N. In patients with VT, AS shows more delay than A. In addition, AS with VT shows lower integral value than AS without VT, however no differences were observed between A with VT and without VT. We conclude that slow upstroke of signal-averaged QRS complex was mainly observed in patients of anteroseptal MI with VT, suggesting the initial conduction delay at ventricular septum may play an important role in the mechanism of VT.
通过信号平均心电图（SAE）对晚期电位（LP）进行无创记录，对于预测室性心动过速（VT）很有用，尤其是在心肌梗死（MI）患者中。然而，在前壁或前间隔心肌梗死中，LP阳性率不够高，无法获得临床意义，因为LP已被QRS波群掩盖。本研究的目的是评估心肌梗死患者初始延迟的临床意义。80例心肌梗死患者分为四组：AS组（前间隔，n = 18，包括6例室性心动过速）、A组（前壁，n = 22，7例室性心动过速）、I组（下壁，n = 28，9例室性心动过速）和P组（后壁，n = 12，无室性心动过速）。20例非心肌梗死患者作为正常对照（N）。使用NEC7T18记录SAE，并测量从初始上升到60毫秒点的滤波后QRS波群的每5毫秒积分值。AS组和A组的积分值明显低于I组、P组和N组。在室性心动过速患者中，AS组的延迟比A组更多。此外，有室性心动过速的AS组的积分值低于无室性心动过速的AS组，然而有室性心动过速和无室性心动过速的A组之间未观察到差异。我们得出结论，信号平均QRS波群的缓慢上升主要见于前间隔心肌梗死合并室性心动过速的患者，提示室间隔的初始传导延迟可能在室性心动过速的机制中起重要作用。
