Meeder R J, Stroink G, Ritcey S P, Gardner M J, Horacek B M
Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
Eur Heart J. 1999 Aug;20(15):1126-34. doi: 10.1053/euhj.1998.1482.
To investigate the ability of spectral features of signal-averaged body-surface potential maps in identifying post-infarction patients who are at risk of developing ventricular tachycardia.
We recorded 120 lead body surface potential maps during sinus rhythm in 135 subjects (45 patients with healed myocardial infarction but no history of ventricular tachycardia, 45 patients with both healed myocardial infarction and at least one episode of sustained ventricular tachycardia, and 45 normal subjects) and analysed spectral features of body surface potential maps selected on the basis of isoharmonic maps for given bands of the frequency spectrum. We found that in the low-frequency band (1-11 Hertz), the group-mean power spectra of leads located at isoharmonic map maxima were significantly different (P<0.0001) between the two groups of myocardial infarction patients. We estimated that this single feature alone can prospectively identify myocardial infarction patients at risk for ventricular tachycardia with a predictive accuracy of 74+/-6%.
Our results suggest that the bulk of diagnostic information associated with arrhythmogenicity resides in the low-frequency band of the power spectrum. This finding is at variance with the established notion that only the high-frequency component of signal-averaged electrocardiograms carries such information.
研究信号平均体表电位图的频谱特征识别有发生室性心动过速风险的心肌梗死后患者的能力。
我们在135名受试者（45名心肌梗死已愈合但无室性心动过速病史的患者、45名心肌梗死已愈合且至少有一次持续性室性心动过速发作的患者以及45名正常受试者）的窦性心律期间记录了120导联体表电位图，并分析了根据给定频段的等谐波图选择的体表电位图的频谱特征。我们发现，在低频带（1 - 11赫兹），两组心肌梗死患者中位于等谐波图最大值处导联的组平均功率谱存在显著差异（P<0.0001）。我们估计，仅这一单一特征就可以前瞻性地识别有室性心动过速风险的心肌梗死患者，预测准确率为74±6%。
我们的结果表明，与致心律失常性相关的大部分诊断信息存在于功率谱的低频带。这一发现与已确立的观念不同，即认为只有信号平均心电图的高频成分携带此类信息。
