Changes in Follow‐Up ECG and Signal‐Averaged ECG in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND: Electrocardiogram (ECG) and signal-averaged ECG (SAECG) are important as diagnostic tools in arrhythmogenic right ventricular cardiomyopathy (ARVC). The aim of this study was to investigate changes in follow-up ECGs and SAECGs in patients with ARVC. METHODS: We collected 185 follow-up ECGs from 38 patients and 35 follow-up SAECGs from 18 patients during a mean follow-up period of 64 ± 36 months. RESULTS: On baseline ECG and SAECG, epsilon waves, T-wave inversion (TWI), and terminal activation delay (TAD) of QRS ≥ 55 ms in right precordial leads, and late potentials (LPs) were observed in six (16%), 11 (29%), 13 (34%), and 23 (68%) patients, respectively. During the follow-up period, 15 (39%) patients had 18 changes in ECG and/or SAECG features included in modified Task Force Criteria (TFC) of ARVC. Two patients developed new epsilon waves, and another two patients had dynamic epsilon waves. Newly developed TAD of QRS ≥ 55 ms was observed in two patients and disappeared in one patient. Eight patients, seven with and one without TWI in V1 -V3 or beyond, showed dynamic changes. LP developed in three patients. One patient with dynamic change of TWI and another patient with dynamic change of epsilon wave and TAD of QRS ≥ 55 ms could not satisfy the modified TFC during follow-up. CONCLUSIONS: Follow-up ECGs and SAECGs showed changes in 39% of patients with ARVC. Larger studies with a longer follow-up period are needed to investigate the clinical implications of changes in follow-up ECG and SAECG.