DYNAMIC ECG AND SIGNAL-AVERAGED ECG CHANGES IN PATIENTS WITH ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY
Purpose: Arrhythmogenic right ventricular cardiomyo- pathy (ARVC) is a kind of progressive disease and some ECG features are important as diagnostic criteria. However, the evolutional changes of diagnostic ECG and signal-averaged ECG (SAECG) features are not well known.
The aim of this study: was to investigate the diagnostic value of the serial ECG and SAECG in ARVC cohort including many patients with proven major structural right ventricular (RV) abnormalities.
Methods: We collected 139 follow-up ECG from 34 patients (44.2±14.7 years, 19 men) and 14 follow-up SAECG from 12 patients during follow-up of 59.9±33.5 months. T-wave inversion (TWI) in right precordial leads, epsilon waves, localized QRS prolongation greater than 110ms in V1-V3 and late potentials (LP) were analyzed.
Results: Majority of patients had major structural RV abnormalities on 2-D echocardiography and/or ventriculography (n=25, 73.5%) or fibrofatty replacement on endomyocardial biopsy (n=25, 73.5%). On baseline ECG and SAECG, epsilon waves, TWI, localized QRS prolongation and LPs were found in 7 (20.6%), 9 (26.5%), 7 (20.6%) and 17 patients (50.0%), respectively. During follow-up, 12 patients (35.3%) had 14 changes of ECG and/or SAECG features. One patient developed new epsilon waves and another three patients had dynamic epsilon waves. Six patients had dynamic TWI and two patients had dynamic localized QRS prolongation. One patient developed new LPs and another patient had dynamic LPs. Among 12 patients with changes in ECG and/or SAECG, seven patients (58.3%) had both major RV abnormalities and fibrofatty replacement. One patient with dynamic change in ECG and another patient with dynamic change in SAECG could not satisfy Task Force Criteria during follow-up. Follow-up duration was longer in patients with ECG changes (74.8±27.6 years) than in those without (50.7±34.1) (p=0.040). The age, gender, the presence or absence of presenting symptom, family history, and ventricular arrhythmias were not different between the two groups.
Conclusions: Serial ECGs and SAECGs in ARVC cohort including many patients with major structural RV abnormalities had diagnostic significance. Larger studies with longer follow-up are needed to investigate the clinical implications of dynamic changes in ECG and SAECG during follow-up.