Abstract 13084: Epsilon Waves on Electrocardiograms in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy: Relationship to Left Ventricular Invasion or Heart Compression Due to an Enlarged Right Ventricle

Abstract

Introduction: Epsilon waves on V1-3 leads are known as one of the specific lead ECG findings in patients with arrhythmogenic right ventricular (RV) cardiomyopathy (ARVC) that suggests the presence of RV conduction delay. Four dimensional (4D) cardiac CT visualizes ARVC characteristics, such as fat and fibrotic invasion in RV (RVM) and left ventricular (LV) myocardium (LVM), an enlarged RV, reduced RV motion, and bulging. Hypothesis: If epsilon waves are observed in V4-6 leads, this finding suggests the occurrence of LV invasion in ARVC. Another hypothesis exists in which extreme RV enlargement may compress the LV and cause clockwise rotation; an enlarged RV itself may cause epsilon waves in V4-6 leads. Methods: This is a retrospective analysis of 17 patients (11 males, 57 ± 17 years) with suspected ARVC who underwent cardiac CT. On 4D CT, nine met 2010 ARVC task force criteria. Results: All nine patients had epsilon waves on ECG. Five had fat and fibrotic invasion in the LVM but four did not. We divided nine into the following five groups by CT findings. On CT, a markedly enlarged RV compressed the LV to the left side and a fibro fatty change were observed exclusively in RVM (gp 1, N=1) or were observed in both RVM and LVM (gp 2, N=2). A moderately enlarged RV without compression of the LV to the left side and a fibro fatty change were observed exclusively in RVM (gp 3, N=3), or observed in both RVM and LVM (gp 4, N=2). The complications of severe mitral valve regurgitation, a markedly enlarged LV, and a fibro fatty change were observed in both RVM and LVM (gp 5, N=1). A patient in gp 1 showed epsilon waves in V1-6 leads. Patients in gp 2 showed epsilon waves in V1-6 (N=1), and V3-5 (N=1) leads, respectively. Patients in gp 3 showed epsilon waves in V1-4 (N=2), and V1-3 (N=1) leads, respectively. Patients in gp 4 showed epsilon waves in V1-3 (N=1), and V1, 2 (N=1) leads, respectively. A patient in gp 5 showed epsilon waves in V4-6 leads. Conclusions: The distribution of epsilon waves on ECG in patients with confirmed ARVC by cardiac CT was highly influenced by the degree of LV compression due to a markedly enlarged RV on CT rather than the presence of LV invasion. Also, structural change due to complicated heart diseases, such as valvular diseases, may also influence the distribution of epsilon waves in ARVC.