Kubo M, Matsuoka S, Hayabuchi Y, Akita H, Matsuka Y, Kuroda Y
Department of Pediatrics, School of Medicine, University of Tokushima, Japan.
Clin Cardiol. 1993 Oct;16(10):723-8. doi: 10.1002/clc.4960161007.
The clinical significance of an abnormal signal-averaged electrocardiogram (SA-ECG) in time- and frequency-domain analyses was assessed in patients with Duchenne muscular dystrophy (DMD). Twenty-four DMD patients and 20 age-matched healthy volunteers were studied. The SA-ECG was recorded by time-domain signal processing using the vector-magnitude method and frequency-domain signal processing using the fast-Fourier transform. Abnormal SA-ECGs were based on comparison with controls and eight abnormal SA-ECGs were detected among 24 DMD patients, seven by frequency-domain analysis and four by time-domain analysis. The end-diastolic left ventricular volume was larger in the patients with abnormal SA-ECG than in those with normal SA-ECG (136 +/- 32 ml vs. 77 +/- 43 ml, p < 0.01). Compared with patients with normal SA-ECGs, the DMD patients with abnormal SA-ECGs had a lower left ventricular (LV) ejection fraction (54 +/- 6 vs. 61 +/- 8%, p < 0.05), as an index of LV contractility, and less LV posterior wall velocity (46 +/- 9 mm/min vs. 62 +/- 16 mm/min, p < 0.01), as an index of LV relaxation. The sensitivity and specificity of frequency-domain analysis for predicting malignant ventricular arrhythmias was 60 and 85%, respectively, compared with 30 and 92%, respectively, for time-domain analysis. The combination of time- and frequency-domain analyses can facilitate identification of DMD patients with ventricular tachyarrhythmias associated with depression of cardiac performance.
在杜兴氏肌营养不良症（DMD）患者中评估了时域和频域分析中异常信号平均心电图（SA-ECG）的临床意义。研究了24例DMD患者和20名年龄匹配的健康志愿者。通过使用矢量幅度法的时域信号处理和使用快速傅里叶变换的频域信号处理来记录SA-ECG。异常SA-ECG是基于与对照组的比较，在24例DMD患者中检测到8例异常SA-ECG，频域分析检测到7例，时域分析检测到4例。SA-ECG异常的患者舒张末期左心室容积大于SA-ECG正常的患者（136±32 ml对77±43 ml，p<0.01）。与SA-ECG正常的患者相比，SA-ECG异常的DMD患者左心室（LV）射血分数较低（54±6对61±8%，p<0.05），作为LV收缩性的指标，LV后壁速度较低（46±9 mm/min对62±16 mm/min，p<0.01），作为LV舒张的指标。频域分析预测恶性室性心律失常的敏感性和特异性分别为60%和85%，而时域分析分别为30%和92%。时域和频域分析相结合可以有助于识别患有与心脏功能下降相关的室性快速心律失常的DMD患者。
