Horácek B M, Warren J W, Stóvícek P, Feldman C L
Faculty of Medicine of Dalhousie University, Halifax, Nova Scotia, Canada.
J Electrocardiol. 2000;33 Suppl:155-60. doi: 10.1054/jelc.2000.20295.
To compare the diagnostic yield of electrocardiograms (ECGs) recorded by 12 standard leads with that of 12-lead ECGs derived from 3 bipolar EASI leads, we analyzed pertinent ECG data for 290 normal subjects and 497 patients who had had a prior myocardial infarction (MI); the latter group comprised 36 patients with a non-Q MI, 282 patients with a Q-wave MI, and 179 patients with a history of ventricular tachycardia (VT). We first estimated statistically an optimal set of coefficients for deriving the 12 standard leads from EASI leads and assessed this transformation in terms of goodness of fit. To gauge the diagnostic information content of the recorded vs. derived 12-lead ECGs, we performed successively two-group diagnostic classification--based on the Cardiac Infarction Injury Score (CIIS)--separating each of the patient subgroups from the normal group; the classification was repeated for 200 sets of patients selected randomly (with replacement), and the results were plotted as mean receiver operating characteristics. We found that derived 12-lead ECGs correlated well with the recorded ones, and reproduced faithfully the diagnostic features needed for the CIIS. When the CIIS was determined from features of the recorded standard 12 leads, its mean diagnostic performance (assessed in terms of area under the receiver operating characteristics curve) was 0.9004 for detecting non-Q MIs, 0.9546 for Q-wave MIs, and 0.9919 for MIs complicated by a history of VT. When, instead, features of derived 12 leads were used to determine the CIIS, diagnostic performance remained virtually unchanged (at 0.8905, 0.9531, and 0.9906, respectively). We conclude that, in our population, EASI-derived 12-lead ECGs contain nearly the same diagnostic information as standard 12-lead ECGs.
为比较12个标准导联记录的心电图（ECG）与源自3个双极EASI导联的12导联ECG的诊断效能，我们分析了290名正常受试者和497例曾患心肌梗死（MI）患者的相关ECG数据；后一组包括36例非Q波MI患者、282例Q波MI患者和179例有室性心动过速（VT）病史的患者。我们首先通过统计学方法估计从EASI导联导出12个标准导联的最佳系数集，并根据拟合优度评估这种转换。为评估记录的与导出的12导联ECG的诊断信息含量，我们基于心肌梗死损伤评分（CIIS）进行了连续的两组诊断分类，将每个患者亚组与正常组区分开；对随机选择（可重复）的200组患者重复进行分类，并将结果绘制成平均受试者工作特征曲线。我们发现，导出的12导联ECG与记录的ECG相关性良好，并忠实地再现了CIIS所需的诊断特征。当根据记录的标准12导联的特征确定CIIS时，其检测非Q波MI的平均诊断性能（根据受试者工作特征曲线下面积评估）为0.9004，检测Q波MI为0.9546，检测合并VT病史的MI为0.9919。相反，当使用导出的12导联的特征来确定CIIS时，诊断性能几乎保持不变（分别为0.8905、0.9531和0.9906）。我们得出结论，在我们的研究人群中，源自EASI的12导联ECG包含与标准12导联ECG几乎相同的诊断信息。
