Goldberger A L, Bhargava V, Froelicher V, Covell J
Circulation. 1981 Jul;64(1):34-42. doi: 10.1161/01.cir.64.1.34.
Studies have shown that the number of high-frequency QRS notches increases after myocardial infarction (MI). To assess overall high-frequency (greater than 80 Hz) potentials more quantitatively, we adapted filtered and the root-mean-square (RMS) voltage of the residual (80-300 Hz) signal computed. High-frequency RMS values were significantly (p less than 0.01) greater in leads II, III and aVf in normal subjects (n = 12) than in patients with inferior infarction (n = 12). Similarly, high-frequency RMS values were higher (p less than 0.01) in leads V2 and V5 in normal subjects (n = 14) than in patients with prior anterior MI (n = 14). A reduction in high-frequency RMS values with inferior infarction was independently confirmed using Fourier analysis of the QRS in lead II. QRS notching in these subjects was also quantified by computing the number of baseline crossings of the first derivative (dV/dt). As predicted, notching was significantly greater (p less than 0.05) both with inferior MI (lead II) and anterior MI (lead V5). However, contrary to classic theory, the number of notches correlated negatively with direct measurements of high-frequency RMS voltage in lead II (r = -0.63) and lead V5 (r = -0.49). Positive correlations were obtained between high-frequency potentials and two new indexes that measure the amplitude of QRS dV/dt-peak-to-peak amplitude of dV/dt and RMS dV/dt. Using these indexes, absolute separation of inferior MI patients and normal subjects was obtained. We conclude that MI increases low-amplitude QRS notching but diminishes total high-frequency voltage, probably because of an overall decrease in electromotive potentials and slowing of ventricular conduction.
研究表明，心肌梗死（MI）后高频QRS切迹的数量会增加。为了更定量地评估整体高频（大于80Hz）电位，我们采用了滤波后的剩余（80 - 300Hz）信号的均方根（RMS）电压进行计算。正常受试者（n = 12）中，II、III和aVf导联的高频RMS值显著（p小于0.01）高于下壁梗死患者（n = 12）。同样，正常受试者（n = 14）中V2和V5导联的高频RMS值高于既往前壁心肌梗死患者（n = 14）（p小于0.01）。通过对II导联QRS进行傅里叶分析，独立证实了下壁梗死患者高频RMS值降低。这些受试者的QRS切迹也通过计算一阶导数（dV/dt）的基线交叉数进行量化。正如预期的那样，下壁心肌梗死（II导联）和前壁心肌梗死（V5导联）时切迹均显著增加（p小于0.05）。然而，与经典理论相反，切迹数量与II导联（r = -0.63）和V5导联（r = -0.49）高频RMS电压的直接测量值呈负相关。高频电位与两个测量QRS dV/dt峰峰值幅度和RMS dV/dt的新指标之间存在正相关。使用这些指标，可实现下壁心肌梗死患者与正常受试者的绝对区分。我们得出结论，心肌梗死会增加低幅QRS切迹，但会降低总高频电压，这可能是由于电动势总体下降和心室传导减慢所致。
