Automated analysis of the 12-lead electrocardiogram to identify the exit site of postinfarction ventricular tachycardia

Heart Rhythm, 02/27/2012

Yokokawa M et al. – The 12–lead ECG of postinfarction ventricular tachycardia (VT) contains localizing information that enables determination of a region of interest in the 10–20 cm2 range for more than 70% of VT exit sites in a given sector.


  • 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 cm2.
  • he median spatial resolution of the 12–lead ECG pattern of the pace maps for a particular region was 15 cm2.

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