Watanabe T, Yamaki M, Tachibana H, Kubota I, Tomoike H
First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Jpn Circ J. 1998 Nov;62(11):844-8. doi: 10.1253/jcj.62.844.
The high frequency components contained in the QRS complex (HF-QRS) are a powerful indicator for the risk of sudden cardiac death. However, it is controversial whether conduction delay increases or decreases the HF-QRS. In 21 anesthetized, open-chest dogs, the right atrium was constantly paced. A cannula was inserted into the left anterior descending artery and flecainide, lidocaine or disopyramide was infused to slow the local conduction. Sixty unipolar electrograms were recorded from the entire ventricular surface and were signal-averaged. Data were filtered (30-250 Hz) by using fast-Fourier transform. The HF-QRS was calculated by integrating the filtered QRS signal. Activation time (AT; dV/dt minimum) was delayed and the HF-QRS was reduced in the area perfused by flecainide, lidocaine or disopyramide. The percent increase in AT closely correlated the percentage decrease in the HF-QRS; the correlation coefficients were 0.75, 0.83 and 0.76 for flecainide, lidocaine and disopyramide infusion, respectively, (p<0.001). Decrease in the HF-QRS linearly correlated with the local conduction delay. This study proved that conduction delay decreases the HF-QRS, and that the HF-QRS is a potent indicator of disturbed local conduction.
QRS波群中包含的高频成分（HF-QRS）是心脏性猝死风险的有力指标。然而，传导延迟会增加还是降低HF-QRS仍存在争议。在21只麻醉开胸犬中，持续对右心房进行起搏。将一根套管插入左前降支动脉，输注氟卡尼、利多卡因或丙吡胺以减慢局部传导。从整个心室表面记录60个单极电图并进行信号平均。使用快速傅里叶变换对数据进行滤波（30 - 250Hz）。通过对滤波后的QRS信号进行积分来计算HF-QRS。在氟卡尼、利多卡因或丙吡胺灌注区域，激活时间（AT；dV/dt最小值）延迟，HF-QRS降低。AT的增加百分比与HF-QRS的降低百分比密切相关；氟卡尼、利多卡因和丙吡胺输注时的相关系数分别为0.75、0.83和0.76，（p<0.001）。HF-QRS的降低与局部传导延迟呈线性相关。本研究证明传导延迟会降低HF-QRS，并且HF-QRS是局部传导紊乱的有效指标。
