Oikarinen L, Viitasalo M, Korhonen P, Väänänen H, Hänninen H, Montonen J, Mäkijärvi M, Katila T, Toivonen L
Department of Medicine, Helsinki University Central Hospital, Finland.
J Cardiovasc Electrophysiol. 2001 Oct;12(10):1115-20. doi: 10.1046/j.1540-8167.2001.01115.x.
Experimentally, both delayed ventricular conduction and nonhomogeneous ventricular repolarization contribute to reentrant arrhythmias. We tested the hypothesis that increased T wave dispersion is independent of delayed ventricular conduction associated with arrhythmia vulnerability in postmyocardial infarction (post-MI) patients.
We studied 32 post-MI patients with clinical or inducible monomorphic ventricular tachycardia (VT group), 28 post-MI patients without arrhythmias (MI group), and 13 healthy controls, using magnetocardiographic (MCG) mapping with signal averaging. Twelve-lead ECG was the reference. Filtered QRS duration (fQRS) and T wave peak to T wave end interval (TPE) were used as measures of ventricular conduction and nonhomogeneity in ventricular repolarization, respectively. In MCG, the VT group showed the longest fQRS (135+/-34 msec vs 114+/-22 msec in the MI group; P = 0.012). Mean TPE and maximum TPE in VT versus MI groups were 78+/-9 msec versus 70+/-6 msec (P < 0.001) and 117+/-23 msec versus 104+/-19 msec (P = 0.020), respectively. Maximum TPE did not correlate with fQRS in the VT group (r = 0.063; P = NS) but did correlate in the MI group (r = 0.396; P = 0.037). For identification of post-MI patients prone to VT, selection of cutoff values for fQRS >140 msec and mean TPE >81 msec gave sensitivity and specificity of 41% and 89%, and 31% and 96%, respectively. Their combination increased sensitivity to 63% while maintaining 89% specificity.
Post-MI patients susceptible to VT show increased T wave dispersion independent of delayed ventricular conduction.
在实验中，心室传导延迟和心室复极不均一均与折返性心律失常有关。我们检验了这样一个假设，即T波离散度增加与心肌梗死后（post-MI）患者心律失常易感性相关的心室传导延迟无关。
我们研究了32例有临床或可诱发单形性室性心动过速的心肌梗死患者（室性心动过速组）、28例无心律失常的心肌梗死患者（心肌梗死组）和13名健康对照者，采用带信号平均的磁心动图（MCG）标测。以12导联心电图作为对照。滤波后的QRS波时限（fQRS）和T波峰至T波终点间期（TPE）分别用作心室传导和心室复极不均一性的指标。在MCG中，室性心动过速组的fQRS最长（135±34毫秒，而心肌梗死组为114±22毫秒；P = 0.012）。室性心动过速组与心肌梗死组的平均TPE和最大TPE分别为78±9毫秒对70±6毫秒（P < 0.001）和117±23毫秒对104±19毫秒（P = 0.020）。室性心动过速组的最大TPE与fQRS不相关（r = 0.063；P =无显著性差异），但在心肌梗死组中相关（r = 0.396；P = 0.037）。为了识别易发生室性心动过速的心肌梗死患者，选择fQRS>140毫秒和平均TPE>81毫秒的临界值，敏感性和特异性分别为41%和89%，以及31%和96%。两者结合可将敏感性提高到63%，同时保持89%的特异性。
易发生室性心动过速的心肌梗死患者表现出T波离散度增加，且与心室传导延迟无关。
