Arrhythmogenic right ventricular cardiomyopathy patients with a markedly enlarged RV compressing LV to left side have an atypical distribution of epsilon waves and elevated plasma BNP

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Epsilon waves on V1-3 leads are specific ECG findings in patients with arrhythmogenic right ventricular (RV) cardiomyopathy (ARVC) suggesting RV conduction delay. Four dimensional (4D) cardiac CT visualizes ARVC characteristics, such as fibro-fatty invasion into RV and left ventricular (LV) myocardium (RVM, LVM), an enlarged RV, reduced RV motion, and bulging.

We hypothesize that Epsilon waves in V4-6 leads suggest LV invasion in ARVC. Alternatively, extreme RV enlargement may compress the LV and cause clockwise rotation; an enlarged RV may itself cause epsilon waves in V4-6 leads.

Retrospective analysis of 17 patients (11 males, 57 ± 17 yrs) with suspected ARVC undergoing cardiac CT and ECG, 9 of whom met 2010 ARVC task force criteria.

All 9 patients had epsilon waves on ECG; 5 had fibro-fatty invasion into the LVM. We divided the 9 into 5 groups by CT: 1) markedly enlarged RV compressing the LV to the left side with fibro-fatty changes exclusively in RVM (N = 1); 2) similar findings in both RVM and LVM (N = 2); 3) moderately enlarged RV without compression of the LV to the left side and fibro-fatty changes exclusively in RVM (N = 3); 4) the same in both RVM and LVM (N = 2); 5) severe mitral valve regurgitation, a markedly enlarged LV, and a fibro-fatty change in both RVM and LVM (N = 1). The patient in group (gp) 1 showed epsilon waves in V1-6 leads, patients in gp 2 had epsilon waves in V1-6 (N = 1), and V3-5 (N = 1) leads; patients in gp 3 had epsilon waves in V1-4 (N = 2), and V1-3 (N = 1) leads, patients in gp 4 had epsilon waves in V1-3 (N = 1), and V1, 2 (N = 1) leads; finally, the patient in gp 5 had epsilon waves in V4-6 leads. Plasma brain natriuretic peptide (BNP) levels were significantly greater in patients in gp 1 & 2 than gp 3 & 4 (1255 ± 838 vs 80 ± 52 pg/ml, P = 0.016).

ARVC patients with a markedly enlarged RV compressing the LV to the left side (gp 1,2) had a broad (V1-6) or different range (V3-5) distribution of epsilon waves and significantly elevated plasma BNP independent of fibro-fatty invasion of the LV, different from typical ARVC (gp 3,4). Additionally, structural change due to complicated heart disease, such as valvular disease (gp5), may also influence the distribution of epsilon waves in ARVC.

Abstract Figure. CT and ECG in ARVC group 1