PO-05-002 ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY WITH EXTENSIVE ABNORMAL SUBSTRATE: IS ISOLATION POSSIBLE?

Abstract

In arrhythmogenic right ventricular cardiomyopathy (ARVC) patients with extensive right ventricular free wall (RVFW) abnormal substrate, large area homogenization with combined epicardial and endocardial approach is time consuming and often inadequate for modification. We aim to explore the feasibility and efficacy of RVFW abnormal substrate isolation in such patients to control ventricular tachycardia (VT). Eight consecutive ARVC patients with VT who had extensive abnormal RVFW substrate were included. VT induction was performed before substrate mapping and modification. Detailed voltage mapping was done during sinus rhythm. A circumferential linear lesion was deployed along the border zone of low-voltage-area on the RVFW to achieve electrical isolation. Other small areas with fractionated or late potentials were further homogenized. All eight patients had extensive RV endocardial low-voltage-area (113.8 ± 84.1 cm2, 49.6 ± 29.8%) and dense scar (59.6 ± 39.8 cm2, 25.0 ± 14.1%). Electrical isolation of abnormal substrate was achieved in 5/8 (62.5%) patients via endocardial approach alone and 3/8 (37.5%) patients via a combination of endocardial and epicardial approach. Electrical isolation was verified by slow automaticity (5/8, 62.5%) or RV non-capture (3/8, 37.5%) during high output pacing inside the encircled area. VTs were induced in 6 patients before ablation and all patients rendered non-inducible after ablation. During a median follow-up of 43 months (range 24-53), 7/8 (87. 5%) patients remained free of sustained VT. Electrical isolation of RVFW is feasible and effective in ARVC patients with extensive abnormal substrate and is associated with excellent long-term rhythm control.