Association of regional epicardial right ventricular electrogram voltage amplitude and late gadolinium enhancement distribution on cardiac magnetic resonance in patients with arrhythmogenic right ventricular cardiomyopathy: Implications for ventricular tachycardia ablation

Criteria for identification of anatomic ventricular tachycardia substrates in arrhythmogenic right ventricular cardiomyopathy (ARVC) on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) are unclear. The purpose of this study was to define (1) the association of regional right ventricular (RV) epicardial voltage amplitude with the distribution of LGE; and (2) appropriate image signal intensity (SI) thresholds for ventricular tachycardia substrate identification in ARVC. Preprocedural LGE-CMR and epicardial electrogram mapping were performed in 10 ARVC patients. The locations of epicardial electrogram map points, obtained during sinus rhythm with intrinsic conduction or RV pacing, were retrospectively registered to the corresponding LGE image regions. Standardized SI z-scores (standard deviation distance from the mean) were calculated for each 10-mm region surrounding map points. In patient-clustered, generalized estimating equations models that included 3205 epicardial electroanatomic points and corresponding SI measures, bipolar (–1.43 mV/z-score; P