Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, USA.
Heart Rhythm. 2012 Mar;9(3):330-4. doi: 10.1016/j.hrthm.2011.10.014. Epub 2011 Oct 12.
The value of the 12-lead electrocardiogram (ECG) to identify the exit site of postinfarction ventricular tachycardia (VT) has been questioned. The purpose of this study was to assess the accuracy of a computerized algorithm for identifying a VT exit site on the basis of the 12-lead ECG.
In 34 postinfarction patients, pace mapping was performed from within scar tissue. A computerized algorithm that used a supervised learning method (support vector machine) received the digitized pace-map morphologies combined with the pacing sites as training data. No other information (ie, infarct localization, bundle branch block morphology, axis, or R-wave pattern) was used in the algorithm. The training data were validated in 58 VTs in 33 patients. The sizes of 10 different anatomic sections within the heart were determined by using the pace maps as the determining factor. Accuracy was found to be 69% for pace maps, and when 2 adjacent regions were combined, accuracy improved to 88%. Validation of the data in 33 patients showed an accuracy of 71% for localizing a VT exit site to 1 of the 10 regions within the left ventricle. If combined with the best adjacent region, accuracy improved to 88%. The median anatomic size of each section was 21 cm(2). The median spatial resolution of the 12-lead ECG pattern of the pace maps for a particular region was 15 cm(2).
The 12-lead ECG of postinfarction VT contains localizing information that enables determination of a region of interest in the 10-20 cm(2) range for more than 70% of VT exit sites in a given sector.
12 导联心电图（ECG）识别心肌梗死后室性心动过速（VT）的出口部位的价值一直存在争议。本研究旨在评估基于 12 导联 ECG 的计算机算法识别 VT 出口部位的准确性。
在 34 例心肌梗死后患者中，进行了心内膜标测。一种计算机算法使用有监督学习方法（支持向量机），将数字化的心内膜标测形态与起搏部位相结合作为训练数据。算法中不使用其他信息（即梗死定位、束支传导阻滞形态、轴位或 R 波形态）。训练数据在 33 例患者的 58 例 VT 中进行了验证。通过使用起搏图作为决定因素，确定了心脏内 10 个不同解剖区域的大小。起搏图的准确率为 69%，当 2 个相邻区域结合时，准确率提高到 88%。在 33 例患者的数据验证中，将 VT 出口部位准确定位到左心室 10 个区域之一的准确率为 71%。如果与最佳相邻区域结合，准确率提高到 88%。每个区域的平均解剖面积为 21cm²。起搏图 12 导联 ECG 模式特定区域的平均空间分辨率为 15cm²。
心肌梗死后 VT 的 12 导联 ECG 包含定位信息，可确定特定区域感兴趣的 10-20cm² 范围，该范围可用于 70%以上的特定扇区的 VT 出口部位。
