12-Lead Electrocardiogram to Localize Region of Abnormal Electroanatomic Substrate in Arrhythmogenic Right Ventricular Cardiomyopathy

Abstract Objectives The purpose of this study was to evaluate the relationship between electrocardiogram (ECG) QRS fragmentation (fQRS) and right ventricular (RV) endocardial (ENDO) and epicardial (EPI) electroanatomic substrate abnormalities in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Background fQRS is frequently observed in patients with ARVC and reflects delayed conduction due to RV fibrosis. Methods A total of 30 consecutive patients met the task force criteria for ARVC (19 men, mean age 41.1 ± 14.3 years) presenting for ventricular tachycardia ablation with detailed RV ENDO and EPI electroanatomic maps were included. Of these, 25 patients had depolarization abnormalities (fragmentation during and/or immediately after the QRS complex [fQRS]) in ≥2 contiguous ECG leads. Inferior (II, III, aVF) fQRS was identified in 23, anterior (V1 to V3 ) in 15, and basal superior (I/aVR) in 11 patients. The surface area and anatomic distribution of ENDO and EPI bipolar low-voltage regions (ENDO ≤1.5 mV,