Beker A, Pinchas A, Erel J, Abboud S
Medical Physics Group, Tel-Aviv University, Israel.
Pacing Clin Electrophysiol. 1996 Dec;19(12 Pt 1):2040-50. doi: 10.1111/j.1540-8159.1996.tb03277.x.
High resolution ECG waveforms from leads V3, V4, V5, and V6 were analyzed in two groups of male subjects before, during, and following treadmill exercise testing. Group A included 32 coronary artery disease (CAD) patients, with arteriographically proven > 75% obstruction of at least two main coronary arteries, and group B included 30 healthy subjects, without history or symptoms of CAD. Signal averaging and filtering techniques were used in order to enhance the signal-to-noise ratio of the recorded ECG. The averaged QRS waveforms were filtered between 150 and 250 Hz. QRS complexes of the four leads were combined to form a "precordial average complex" (PAC). The PAC signals were examined for each subject at different stages of the exercise test and two parameters were computed: the root mean square (RMS) voltage; and the peak amplitude. The values of RMS and peak amplitudes measured at each stage of the exercise test were normalized to the values at rest. Normalized RMS (NRMS) values at peak exercise, immediately after peak exercise, and during the recovery phase were found to be higher for the healthy subjects than for the CAD group (1.17 +/- 0.31 vs 0.94 +/- 0.26, P < 0.008 at peak exercise, 1.13 +/- 0.24 vs 0.84 +/- 0.19, P < 0.001 after peak exercise, 1.08 +/- 0.22 vs 0.94 +/- 0.17, P < 0.007 during recovery). Cut-off NRMS value of one had a sensitivity of 81.3% and a specificity of 70.0% in differentiating CAD patients from healthy subjects in the examined groups. Normalized peak amplitude (NAMP) values exhibited similar behavior, with higher values for the healthy subjects than for the CAD group (1.23 +/- 0.48 vs 0.94 +/- 0.36, P < 0.03 at peak exercise, 1.20 +/- 0.34 vs 0.83 +/- 0.28, P < 0.001 after peak exercise, 1.10 +/- 0.29 vs 0.94 +/- 0.23, P < 0.02 during recovery). Specificity of 73.3% and sensitivity of 71.8% were found using a postpeak NAMP cut-off value of 1. In conclusion, the present study shows that using high frequency ECG may contribute to identifying patients with CAD. Further studies in larger groups of patients are required to better define the true predictive value of the method described for the diagnosis of CAD.
在两组男性受试者进行跑步机运动测试前、测试期间及测试后，对来自V3、V4、V5和V6导联的高分辨率心电图波形进行了分析。A组包括32例冠状动脉疾病（CAD）患者，经血管造影证实至少两条主要冠状动脉阻塞超过75%；B组包括30名健康受试者，无CAD病史或症状。采用信号平均和滤波技术以提高记录心电图的信噪比。平均QRS波形在150至250Hz之间进行滤波。将四个导联的QRS波群组合形成一个“胸前平均复合波”（PAC）。在运动测试的不同阶段对每个受试者的PAC信号进行检查，并计算两个参数：均方根（RMS）电压和峰值幅度。将运动测试各阶段测得的RMS和峰值幅度值与静息值进行归一化处理。发现健康受试者在运动峰值、运动峰值后即刻及恢复阶段的归一化RMS（NRMS）值高于CAD组（运动峰值时为1.17±0.31对0.94±0.26，P<0.008；运动峰值后为1.13±0.24对0.84±0.19，P<0.001；恢复期间为1.08±0.22对0.94±0.17，P<0.007）。在受试组中，以NRMS值1为临界值区分CAD患者与健康受试者时，敏感性为81.3%，特异性为70.0%。归一化峰值幅度（NAMP）值表现出类似的情况，健康受试者的值高于CAD组（运动峰值时为1.23±0.48对0.94±0.36，P<0.03；运动峰值后为1.20±0.34对0.83±0.28，P<0.001；恢复期间为1.10±0.29对0.94±0.23，P<0.02）。使用运动峰值后NAMP临界值1时，特异性为73.3%，敏感性为71.8%。总之，本研究表明，使用高频心电图可能有助于识别CAD患者。需要在更大的患者群体中进行进一步研究，以更好地确定所描述方法对CAD诊断的真正预测价值。
