Reinhardt L, Mäkijärvi M, Fetsch T, Montonen J, Sierra G, Martínez-Rubio A, Katila T, Borggrefe M, Breithardt G
Department of Cardiology and Angiology, Hospital of the Westfälische Wilhelms-Universität, Münster, Germany.
J Am Coll Cardiol. 1996 Jan;27(1):53-9. doi: 10.1016/0735-1097(96)80739-X.
This study sought to evaluate the prognostic value of wavelet correlation functions of the signal-averaged electrocardiogram (ECG) for arrhythmic events in patients after myocardial infarction.
Wavelet transform of the signal-averaged ECG has been shown to be a nonstationary analysis technique describing the time evolution of frequency spectra throughout the QRS complex. To quantify the wavelet transform, we introduced the new concept of the wavelet correlation function.
The relation among wavelet correlation functions, ventricular late potentials and the site of infarction was investigated in 769 men < 66 years old who survived the acute phase of myocardial infarction (351 [46%] anterior, 418 [54%] inferior infarctions). Signal-averaged ECG recordings were obtained 2 to 3 weeks after infarction. During 6 months of follow-up, 33 patients (4.3%) experienced a malignant arrhythmic event. Wavelet correlation functions of the signal-averaged ECG were evaluated in a time-frequency plane ranging from 25 ms before QRS onset to 25 ms after QRS offset in the frequency range between 40 and 100 Hz.
Patients with an anterior infarction had lower mean wavelet correlation coefficients (p < 0.001) and a lower incidence of ventricular late potentials than patients with an inferior infarction (32.3% vs. 42.7%, p = 0.003). The combination of wavelet correlation functions and late potentials increased the total predictive accuracy from 52% to 72% for inferior and from 64% to 76% for anterior infarctions.
Spectral changes in the signal-averaged QRS complex are more prominent in anterior than inferior infarctions. Combination of late potential analysis and wavelet correlation functions increases the prognostic value for serious arrhythmic events after myocardial infarction.
本研究旨在评估信号平均心电图（ECG）的小波相关函数对心肌梗死后患者心律失常事件的预后价值。
信号平均ECG的小波变换已被证明是一种非平稳分析技术，可描述整个QRS波群频谱的时间演变。为了量化小波变换，我们引入了小波相关函数的新概念。
在769名年龄小于66岁且存活过心肌梗死急性期的男性患者中（351例[46%]前壁梗死，418例[54%]下壁梗死），研究小波相关函数、心室晚电位与梗死部位之间的关系。在梗死后2至3周进行信号平均ECG记录。在6个月的随访期间，33例患者（4.3%）发生了恶性心律失常事件。在QRS波起始前25毫秒至QRS波结束后25毫秒、频率范围在40至100赫兹的时频平面内评估信号平均ECG的小波相关函数。
前壁梗死患者的平均小波相关系数较低（p<0.001），心室晚电位的发生率低于下壁梗死患者（32.3%对42.7%，p = 0.003）。小波相关函数和晚电位相结合，下壁梗死的总预测准确率从52%提高到72%，前壁梗死从64%提高到76%。
信号平均QRS波群的频谱变化在前壁梗死中比下壁梗死更明显。晚电位分析与小波相关函数相结合可提高心肌梗死后严重心律失常事件的预后价值。
