Different underlying aetiologies in patients presenting with ventricular tachycardia fulfilling task force criteria for ARVC: initial suspicion based on the 12-lead electrocardiogram

Abstract Background The Task Force Criteria (TFC) for ARVC are highly sensitive, but lack specificity. Patients with atypical RV-involvement (aRVi) may have different underlying aetiologies and prognosis, requiring specific therapeutic interventions. Purpose We aimed to evaluate the role of baseline ECG initial suspicion aRVi. Methods From Netherlands Heart Institute Arrhythmogenic Cardiomyopathy (NHI-ACM) registry, patients were selected who 1) fulfilled TFC definite ARVC, 2) presented sustained VT, 3) underwent genetic testing. first available after VT was evaluated AV-conduction presence surface area (SA) an R'-wave in V1-V3. ECGs disturbances or SA ≥1.65 mm2 classified as suspicious `atypical RV-involvement' (aRVi-ECG). ARVC-related pathogenic/likely pathogenic variant (P/LP+) “typical ARVC”. Data without (P/LP−) reviewed by expert panel either ARVC” “suggestive another aetiology” based on consensus. Results In total 124 P/LP+ 35 P/LP− included. Nineteen had aRVi-ECG, which appeared significantly more predominant group (11 (9%) vs. 8 (22%) P/LP−, p=0.019). Of patients, seventeen (49%) (e.g. myocarditis, ischemia, sarcoid), including all aRVI-ECG. Among 46% carried Arg14del phospolamban 64% died, versus 15% 18% respectively (Table 1). Conclusion For presenting fulfilling diagnosis, a suggestive should raise aetiology P/LP variant. aRVi-ECG identify those poor outcome. Funding Acknowledgement Type funding sources: None.