Abstract 11620: High Prevalence of Catecholamine-Facilitated Focal Ventricular Tachycardia in Patients with Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy
Introduction: Exercise related ventricular tachycardia (VT) and high burden of premature ventricular contractions (PVCs) are common in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). We hypothesized that VT in ARVD/C shows a high degree of association with the ventricular ectopy (VE) at baseline.
Methods: The study population included 16 consecutive ARVD/C patients with recurrent VT who underwent catheter ablation. All patients had history of exercise induced VT and frequent ventricular ectopy. Electrophysiology testing included burst pacing and high dose isoproterenolol infusion (20-30 mcg/min) in addition to programmed stimulation.
Results: Mean age of the patients was 36.4 ± 20.9 years and 50% were men. All patients had frequent ectopy at baseline with a mean PVC count of 6792 6058. During EP study a total of 27 VTs were induced of which 16 (59%) occurred during high dose isoproterenol +/- burst pacing while the remainder were induced by extrastimuli. VT morphology was identical to the baseline PVCs in all the VTs induced during high dose isoproterenol infusion (figure). Focal ablation at the site of earliest activation and 12/12 pacemap of the PVC eliminated the VT in all cases. Target site for focal ablation localized to scar border defined by sinus rhythm voltage map. Cumulative freedom from VT following ablation was 85.2% and 74.5% at 1 and 2 years, respectively, which was associated with reduction in PVC count (2696 2558).
Conclusions: We report a high prevalence of sustained VT during high dose isoproterenol infusion in ARVD/C. More importantly, there is a high degree of association between VEs at baseline and the VTs induced during catecholamine infusion. The site of origin of these VTs localized to the border region of scar with the most common location being the RVOT and RV basal regions. These findings highlight the importance of catecholamine challenge and PVC mapping, which can in turn facilitate ablation of the VT in ARVD/C.
- © 2012 by American Heart Association, Inc.