Multilead Template‐Derived Residua of Surface ECGS for Quantitative Assessment of Arrhythmia Risk

Abstract

Contemporary electrocardiographic (ECG) markers including ventricular ectopy and arrhythmias have not proved reliable in risk assessment for life-threatening arrhythmias. We developed the "Multilead ECG Template-Derived Residua" approach to remove intrinsic morphologic differences and allow calculation of pathologic ECG heterogeneities among spatially separated leads. Prediction by R-wave and T-wave heterogeneity (RWH, TWH) analysis was tested in simulated and clinical ECGs. An enabling description of the Residua algorithm is provided. Simulated ECGs with but not without Residua produced a linear relationship (correlation coefficient r(2) = 0.999) between input and output RWH and TWH values. In heart failure patients, Residua disclosed a marked crescendo in RWH from 164.1 ± 33.1 at baseline to 299.8 ± 54.5 μV and TWH from 134.5 ± 20.6 at baseline to 239.2 ± 37.0 μV at 30-45 minutes before the arrhythmia (both, P < 0.05), which remained elevated until arrhythmia onset. Without Residua, mean RWH and TWH were elevated at 1061.0 ± 222.9 and 882.5 ± 375.2 μV, respectively, throughout the recording and were not different prior to ventricular tachycardia onset. Calculation of ECG-template derived Residua provides a highly accurate means for assessing arrhythmia risk from standard ECGs. Potential widespread applications include resting diagnostic 12-lead, ambulatory, and exercise ECGs, electrophysiologic study laboratory recordings, and implantable devices.