Evaluation of arrhythmogenic substrate in patients with hypertrophic cardiomyopathy using wavelet transform analysis.
Evaluation of arrhythmogenic substrate in patients with hypertrophic cardiomyopathy using wavelet transform analysis.
复制标题
使用小波变换分析评估肥厚型心肌病患者的致心律失常基质。
作者：
H. Takayama;K. Yodogawa;T. Katoh;T. Takano
背景
肥厚型心肌病（HCM）被认为是一种微伏级的心肌电紊乱，导致室性快速性心律失常和心源性猝死。虽然信号平均心电图（ECG）已被用来检测晚电位作为一个参数的电不稳定性，其预测性不高。本研究的重点是高分辨率小波变换的能力，从心跳到心跳的分析，以检测致心律失常的基板，并评估其与室性心动过速的严重程度。
方法和结果
研究组包括50名健康受试者和50名HCM患者。测量信号平均心电图的滤波QRS时限、小波变换心电图的高功率时限（HPD）和紊乱点数（NDP）。以HPD>114 ms和/或NDP >9分为异常时，诊断室性心动过速的敏感性为93.8%，特异性为79.4%。当正常受试者的HPD的平均值+/-标准差被定义为正常时，93.8%的晚电位阳性患者超出正常范围。
结论
新开发的彩色显示三维小波变换系统在分析每一个单拍时显示出良好的时频分辨率，而无需信号平均。该分析可用于检测HCM患者中的致炎底物。
BACKGROUND
Hypertrophic cardiomyopathy (HCM) is thought to have a microvolt-level electrical disarrangement in the myocardium that leads to ventricular tachyarrhythmias and sudden cardiac death. Although signal-averaged electrocardiography (ECG) has been used to detect late potential as a parameter of electrical instability, its predictability is not high. The focus of the present study was the ability of high-resolution wavelet transform from beat-to-beat analysis to detect arrhythmogenic substrates and to evaluate its relationship to the severity of ventricular tachycardia.
METHODS AND RESULTS
The study group comprised 50 healthy subjects and 50 patients with HCM. The filtered-QRS duration from the signal-averaged ECG, the high-power duration (HPD) and number of disarrangement points (NDP) from the wavelet-transform ECG were measured. When HPD was defined >114 ms and/or NDP >9 points as abnormal, the sensitivity and specificity for ventricular tachycardia was 93.8% and 79.4%, respectively. When a mean +/- standard deviation of the HPD in normal subjects was defined as normal, 93.8% of patients with a positive late potential were out of the normal range.
CONCLUSIONS
The newly developed color-display 3-dimensional wavelet transform system showed good time-frequency resolution in analyzing every single beat without signal-averaging. The analysis could be used to detect arrhythmogenic substrates in patients with HCM.