ECG late depolarization abnormality called epsilon wave (ɛ) is a major diagnostic criterion in ARVC/D patients according to Task Force.

As ARVC/D induces progressive right ventricular enlargement, whether or not additional right precordial leads (X1, X2, V3R, V4R) may increase ECG diagnostic sensitivity at rest and/or during exercise has never been systematically investigated.

We studied 3 groups (G) of subjects. G1: 17 propositus patients with desmosomal mutation; G2: 17 first degree relative gene carriers; G3: 20 controls. All subjects were paired between groups for age, BSA, sex and sport practice. A 16 leads ECG including additional right precordial leads X1, X2, V3R, V4R was performed in each case both at rest and at peak stress. Recordings were amplified up to 100mm/s and 40mm/mV and retrospectively analyzed by two investigators blinded to patient status.

All subjects reached a sustained power of similar strength (160±50W) on cycloergometer. At rest, by including standard (V1, V2) and additional right precordial leads, an ɛ was shown in 14/34 patients (41%, 7 in G1, 7 in G2). Among them 4 (12%, 2 in G1, 2 in G2) showed an ɛ exclusively in at least one additional lead. At peak stress, an ɛ was noticed in 19/34 patients (56%, 12 in G1, 7 in G2). Among them, 9 patients (26%, 7 in G1, 2 in G2) showed an ɛ exclusively in at least one additional lead. In other words, in 5/34 patients (15%, all in G1) not showing any ɛ at rest, peak stress unmasked a new ɛ, exclusively in at least one additional right precordial lead. No ɛ was detected in G3, neither at rest nor at stress.

By combining rest and stress test ECG, the use of additional right precordial leads X1, X2, V3R, V4R, enhances by 27% the detection of ɛ waves (major criterion), more often in propositus than in relatives, as compared to usual precordial derivations alone, and should be proposed for inclusion among ARVC/D Task Force criteria.