Kinoshita O, Fontaine G, Rosas F, Elias J, Iwa T, Tonet J, Lascault G, Frank R
Center de Stimulation Cardiaque et de Rythmologie, Hopital Jean Rostand, Ivry, France.
Circulation. 1995 Feb 1;91(3):715-21. doi: 10.1161/01.cir.91.3.715.
Arrhythmogenic right ventricular dysplasia (ARVD) is characterized by recurrent ventricular tachycardia of right ventricular origin and a cardiomyopathy with hypokinetic areas involving the free wall of the right ventricle. Subjects have a risk of sudden cardiac death, particularly during sports and strenuous exercise. Routine clinical examinations may be normal, but fragmented or delayed electrograms are usually recorded in the right ventricle of these patients. However, the frequency with which late potentials are detected by conventional time-domain analysis of the signal-averaged ECG (SAECG) is not high. This study evaluated the usefulness of the frequency-domain analysis of the SAECG in addition to the conventional time-domain analysis for a screening test to detect patients with ARVD.
SAECG was recorded by using a bipolar X, Y, and Z lead system in 28 patients with ARVD (mean age, 38 +/- 13 years) and 35 age-matched normal subjects (mean age, 35 +/- 11 years). The conventional time-domain analysis of the SAECG was performed at two different high-pass filter settings, 25 and 40 Hz, and the low-pass cutoff frequency was fixed at 250 Hz. The fast-Fourier transform analysis of SAECG was performed using a Blackman-Harris window. Area ratio 1 (area of 20 to 50 Hz)/(area of 0 to 20 Hz) and area ratio 2 (area of 40 to 100 Hz)/(area of 0 to 40 Hz) were calculated. In the conventional time-domain analysis, 20 (71%) and 18 (64%) patients had positive criteria at filter settings of 25 and 40 Hz, respectively. In the frequency-domain analysis, 18 (64%) and 20 (71%) patients had abnormal values in area ratios 1 and 2, respectively. Combining the time- and frequency-domain analyses, all patients were judged positive, with a sensitivity of 100% and a specificity of 94%.
Each result of the time- and frequency-domain analyses revealed that both methods had equivalent value. Combining the two domain analyses improved the sensitivity without reducing the specificity. These findings suggest that combining the time- and frequency-domain analyses of the SAECG may be useful as a screening test to detect patients with ARVD.
致心律失常性右室心肌病（ARVD）的特征为起源于右室的反复室性心动过速以及右室游离壁运动减弱区域的心肌病。患者有心脏性猝死风险，尤其是在运动和剧烈锻炼期间。常规临床检查可能正常，但这些患者的右室通常记录到碎裂或延迟的心电信号。然而，通过信号平均心电图（SAECG）的传统时域分析检测晚电位的频率不高。本研究评估了除传统时域分析外，SAECG频域分析用于筛查ARVD患者的有效性。
采用双极X、Y和Z导联系统记录28例ARVD患者（平均年龄38±13岁）和35例年龄匹配的正常受试者（平均年龄35±11岁）的SAECG。SAECG的传统时域分析在两种不同的高通滤波器设置（25和40Hz）下进行，低通截止频率固定为250Hz。使用布莱克曼 - 哈里斯窗对SAECG进行快速傅里叶变换分析。计算面积比1（20至50Hz面积）/（0至20Hz面积）和面积比2（40至100Hz面积）/（0至40Hz面积）。在传统时域分析中，分别有20例（71%）和18例（64%）患者在25Hz和40Hz滤波器设置下符合阳性标准。在频域分析中，分别有18例（64%）和20例（71%）患者的面积比1和面积比2值异常。将时域和频域分析相结合，所有患者均被判定为阳性，敏感性为100%，特异性为94%。
时域和频域分析的每个结果均显示两种方法具有同等价值。将两种域分析相结合可提高敏感性而不降低特异性。这些发现表明，SAECG的时域和频域分析相结合可能作为筛查ARVD患者的有用检测方法。
