Mäkijärvi M, Montonen J, Toivonen L, Siltanen P, Nieminen M S, Leiniö M, Katila T
First Department of Medicine, Helsinki University Central Hospital, Finland.
J Electrocardiol. 1993 Apr;26(2):117-24. doi: 10.1016/0022-0736(93)90003-v.
The value of time domain analysis of late fields in the high-resolution magnetocardiogram in the identification of myocardial infarction patients with ventricular tachycardia was investigated in 30 subjects: 10 patients with documented sustained ventricular tachycardia and old myocardial infarction, 10 patients with old myocardial infarction without complex ventricular arrhythmias, and 10 normal volunteers. The duration of the QRS complex in the magnetocardiogram was significantly longer in ventricular tachycardia patients compared to myocardial infarction patients (144 (SD, 33) vs 109 (SD, 8) ms; p = 0.004). The root-mean-square field of the last 60 ms of the QRS complex was smaller in ventricular tachycardia patients than in myocardial infarction patients (830 (SD, 650) vs 1,480 (SD, 730) fT, respectively; p = 0.047). Also, the duration of the low-amplitude signal less than 700 fT was longer in ventricular tachycardia patients than in myocardial infarction patients (47 (SD, 28) vs 28 (SD, 8) ms, respectively; p = 0.048). The sensitivity and specificity in identifying ventricular tachycardia patients were both 80%, and the positive and negative predictive values were 78% and 86%, respectively. High-resolution electrocardiography recorded during the same session performed slightly better: sensitivity 90%, specificity 90%, and positive and negative predictive values 90%. The signal-to-noise ratio of electrocardiogram was higher (approximately 2 x) than that of magnetocardiogram. It is concluded that the new magnetocardiographic technique seems helpful in screening patients at risk of ventricular arrhythmias after myocardial infarction. The results encourage further refinement of the technique and application in prospective studies.
在30名受试者中研究了高分辨率心磁图晚期场的时域分析在识别伴有室性心动过速的心肌梗死患者中的价值：10例有记录的持续性室性心动过速和陈旧性心肌梗死患者，10例有陈旧性心肌梗死但无复杂室性心律失常的患者，以及10名正常志愿者。与心肌梗死患者相比，室性心动过速患者的心磁图中QRS波群持续时间明显更长（分别为144（标准差，33）ms和109（标准差，8）ms；p = 0.004）。室性心动过速患者QRS波群最后60 ms的均方根场比心肌梗死患者小（分别为830（标准差，650）fT和1480（标准差，730）fT；p = 0.047）。此外，室性心动过速患者中低于700 fT的低振幅信号持续时间比心肌梗死患者长（分别为47（标准差，28）ms和28（标准差，8）ms；p = 0.048）。识别室性心动过速患者的敏感性和特异性均为80%，阳性和阴性预测值分别为78%和86%。在同一时段记录的高分辨率心电图表现稍好：敏感性90%，特异性90%，阳性和阴性预测值均为90%。心电图的信噪比高于心磁图（约2倍）。结论是，新的心磁图技术似乎有助于筛查心肌梗死后有室性心律失常风险的患者。这些结果鼓励进一步改进该技术并将其应用于前瞻性研究。
