Zimmermann M, Adamec R, Simonin P, Richez J
Cardiology Center, Faculty of Medicine, University Hospital, Geneva, Switzerland.
Am Heart J. 1991 Feb;121(2 Pt 1):576-85. doi: 10.1016/0002-8703(91)90728-z.
To detect dynamic changes of VLPs we developed a low-noise, HR-ECG with a gain of 10(5)-10(6)X. This system allows the beat-to-beat detection of low-amplitude signals at the bedside in a nonshielded room without any averaging process. Analysis was performed in 39 normal subjects (group A: 27 men, 12 women, mean age, 28 +/- 8 years), in 98 patients with coronary artery disease without documented sustained ventricular tachycardia (group B: 86 men, 12 women, mean age, 59 +/- 10 years) and in 41 patients coronary artery disease with sustained monomorphic ventricular tachycardia (group C: 36 men, 5 women; mean age 63 +/- 9 years). Comparison was made with time-domain signal-averaging (SA-ECG) in all cases at the same electrode position and with identical band-pass filtering. In group A no VLPs were detected; the total filtered QRS duration was 84 +/- 8 msec (mean +/- SD), and the time interval during which the terminal QRS did not exceed 40 microV (I-40) was less than 30 msec in all cases (mean, 17 +/- 6 msec). In group B, VLPs were detected by HR-ECG in 34 of 98 patients (35%); the total QRS duration was 102 +/- 16 msec (mean +/- SD, p less than 0.01 vs group A), and the I-40 was 29 +/- 13 msec (mean +/- SD, p less than 0.01 vs (group A). In group C, VLPs were detected by HR-ECG in 38 of 41 patients (93%); the total QRS duration was 123 +/- 22 msec (mean +/- SD, p less than 0.01 vs group A and group B), and the I-40 was 40 +/- 14 msec (mean +/- SD, p less than 0.01 vs group A and group B). Concordant results between HR-ECG and SA-ECG were observed in 91% of the cases (59 positive and 103 negative results). Late potentials that exhibited dynamic variations were detected by HR-ECG alone in 13 cases, and very low amplitude VLPs were detected by SA-ECG alone in three cases. In conclusion, the present study demonstrates the feasibility of body-surface recording of VLPs on a beat-to-beat basis, without any averaging process, at the bedside in a nonshielded room. This new approach may allow the study of dynamic changes of VLPs during spontaneous ventricular arrhythmias or ischemia.
为检测心室晚电位（VLPs）的动态变化，我们研发了一种低噪声的高分辨率心电图（HR - ECG），其增益为10(5)-10(6)倍。该系统能够在非屏蔽房间的床边逐搏检测低幅度信号，无需任何平均处理。对39名正常受试者（A组：27名男性，12名女性，平均年龄28±8岁）、98名无持续性室性心动过速记录的冠心病患者（B组：86名男性，12名女性，平均年龄59±10岁）以及41名患有持续性单形性室性心动过速的冠心病患者（C组：36名男性，5名女性；平均年龄63±9岁）进行了分析。在所有病例中，于相同电极位置并采用相同带通滤波，与时域信号平均心电图（SA - ECG）进行比较。A组未检测到VLPs；总滤波QRS时限为84±8毫秒（均值±标准差），所有病例中终末QRS不超过40微伏（I - 40）的时间间隔均小于30毫秒（均值为17±6毫秒）。B组中，98例患者中有34例（35%）通过HR - ECG检测到VLPs；总QRS时限为102±16毫秒（均值±标准差，与A组相比p<0.01），I - 40为29±13毫秒（均值±标准差，与A组相比p<0.01）。C组中，41例患者中有38例（93%）通过HR - ECG检测到VLPs；总QRS时限为123±22毫秒（均值±标准差，与A组和B组相比p<0.01），I - 40为40±14毫秒（均值±标准差，与A组和B组相比p<0.01）。91%的病例（59个阳性结果和103个阴性结果）中HR - ECG与SA - ECG结果一致。仅通过HR - ECG检测到13例表现出动态变化的晚电位，仅通过SA - ECG检测到3例极低幅度的VLPs。总之，本研究证明了在非屏蔽房间的床边无需任何平均处理，逐搏进行体表记录VLPs的可行性。这种新方法可能有助于研究自发性室性心律失常或缺血期间VLPs的动态变化。
