Interlead heterogeneity of R- and T-wave morphology in standard 12-lead ECGs predicts sustained ventricular tachycardia/fibrillation and arrhythmic death in patients with cardiomyopathy

J Cardiovasc Electrophysiol. 2017 Nov;28(11):1324-1333. doi: 10.1111/jce.13288. Epub 2017 Aug 4.

Abstract

Introduction: Nonuniformities in depolarization and repolarization morphology are critical factors in ventricular arrhythmogenesis.

Methods and results: We assessed interlead R-wave heterogeneity (RWH) and T-wave heterogeneity (TWH) in standard 12-lead electrocardiograms (ECGs) using second central moment analysis. This technique quantifies variance about the mean morphology of beats in adjoining precordial leads, V4 , V5 , and V6 in this study. The study was conducted in 120 consecutive patients without an apparent reversible trigger for ventricular tachycardia (VT), recent myocardial infarction, or active ischemia, who presented for electrophysiologic study, implantable cardioverter defibrillator (ICD) placement, or generator change at our institution from 2008 to 2011. Primary outcome was sustained VT/ventricular fibrillation (VF) or appropriate ICD therapies. Secondary outcome was arrhythmic death or resuscitated cardiac arrest. Cutpoints for elevated RWH (>160 μV) and TWH (>80 μV) identified 67% of primary outcome cases and 85% of secondary outcome cases. Cardiomyopathy patients who met the primary outcome (n = 42) had significantly higher TWH than those who did not (n = 28) (TWH: 95 ± 11 μV vs. 44 ± 9 μV, P < 0.002). Likewise, cardiomyopathy patients who met secondary outcome (N = 13) had VT/VF during follow-up and also had significantly higher TWH than survivors (N = 57) (TWH: 105 ± 24 μV vs. 67 ± 8 μV, P < 0.002). Kaplan-Meier analysis revealed significant differences in arrhythmia-free survival (P = 0.012) and total survival (P = 0.011) among cardiomyopathy patients with (n = 37) compared to without (n = 33) elevated RWH and/or TWH independent of age, sex, and left ventricular ejection fraction (LVEF).

Conclusion: Interlead RWH and TWH in 12-lead ECGs predict sustained ventricular arrhythmia, appropriate ICD therapies, and arrhythmic death or cardiac arrest in cardiomyopathy patients independent of LVEF and other standard variables.

Keywords: ECG; arrhythmia; cardiomyopathy; heterogeneity; sudden cardiac death; ventricular tachycardia.

MeSH terms

  • Aged
  • Cardiomyopathies / diagnosis
  • Cardiomyopathies / mortality
  • Cardiomyopathies / physiopathology*
  • Death, Sudden, Cardiac / epidemiology
  • Defibrillators, Implantable / trends*
  • Electrocardiography / trends*
  • Electrodes
  • Female
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Tachycardia, Ventricular / diagnosis
  • Tachycardia, Ventricular / mortality
  • Tachycardia, Ventricular / physiopathology*
  • Ventricular Fibrillation / diagnosis
  • Ventricular Fibrillation / mortality
  • Ventricular Fibrillation / physiopathology*