Malik M, Kulakowski P, Poloniecki J, Staunton A, Odemuyiwa O, Farrell T, Camm J
Department of Cardiological Sciences, St. George's Hospital Medical School, London, England.
J Am Coll Cardiol. 1992 Jul;20(1):127-34. doi: 10.1016/0735-1097(92)90148-g.
Three repeated signal-averaged electrocardiographic (ECG) recordings were made in 40 subjects (15 healthy volunteers, 10 patients with ventricular tachycardia without apparent heart disease and 15 patients with ventricular tachycardia after myocardial infarction). In each subject, the three recordings were made within 25 min. The recordings were subsequently analyzed by 1) the conventional time domain method of signal-averaged ECG analysis with use of filter settings of 25 to 250 Hz and 40 to 250 Hz, 2) a spectral analysis method computing the energy area within the spectral boundaries of 40 to 140 Hz and the ratio between the energies of areas within the boundaries 40 to 140 Hz and 0 to 40 Hz, and 3) spectral temporal mapping computing the "normality factor." The study compared the reproducibility of these three approaches to the analysis of signal-averaged ECGs. First, the reproducibility of the diagnostic conclusions (that is, of the diagnosis of late potentials) was compared for the time domain method and for spectral temporal mapping. Second, the reproducibility of the numeric values of individual indexes provided by different methods was compared for all methods by computing the ratios between standard deviations of measurements in individual patients and standard deviation of all measurements. The reproducibility of diagnostic conclusions was significantly higher for the time domain method than for spectral temporal mapping (p less than 0.05, sign test). The numeric reproducibility of the normality factors produced by spectral temporal mapping was significantly lower than the numeric reproducibility of the values of all indexes provided by time domain, spectral area and spectral area ratio methods (p less than 0.05 to 0.00005, Wilcoxon tests). Spectral temporal mapping was the least reproducible method for the analysis of signal-averaged ECGs.
对40名受试者（15名健康志愿者、10名无明显心脏病的室性心动过速患者和15名心肌梗死后室性心动过速患者）进行了三次重复的信号平均心电图（ECG）记录。在每个受试者中，三次记录在25分钟内完成。随后对记录进行了如下分析：1）采用25至250Hz和40至250Hz的滤波设置，通过信号平均心电图分析的传统时域方法；2）一种频谱分析方法，计算40至140Hz频谱边界内的能量面积以及40至140Hz和0至40Hz边界内区域能量之比；3）频谱时间映射，计算“正常因子”。该研究比较了这三种分析信号平均心电图方法的可重复性。首先，比较了时域方法和频谱时间映射对诊断结论（即晚电位诊断）的可重复性。其次，通过计算个体患者测量值的标准差与所有测量值的标准差之比，比较了所有方法提供的各个指标数值的可重复性。时域方法诊断结论的可重复性显著高于频谱时间映射（p小于0.05，符号检验）。频谱时间映射产生的正常因子的数值可重复性显著低于时域、频谱面积和频谱面积比方法提供的所有指标数值的可重复性（p小于0.05至0.00005，Wilcoxon检验）。频谱时间映射是分析信号平均心电图最不可重复的方法。
