OBJECTIVES: This study sought to evaluate the outcomes of radiofrequency catheter ablation (RFA) of ventricular tachycardia (VT) in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) patients. Particular focus was placed on defining the single-procedure efficacy over long-term follow-up. BACKGROUND: ARVD/C is an inherited cardiomyopathy characterized by VT and right ventricular dysfunction. Prior single-center studies have reported conflicting results concerning the efficacy of RFA of VT in ARVD/C patients. METHODS: The study population comprised 24 patients (age 36 +/- 9 years, 11 male), enrolled in the Johns Hopkins ARVD registry, who underwent 1 or more RFA procedures for treatment of VT. Patients were followed up for 32 +/- 36 months (range 1 day to 12 years). Recurrence was defined as the documentation of VT subsequent to the procedure. RESULTS: A total of 48 RFA procedures were performed using 3-dimensional electroanatomical (n = 10) or conventional (n = 38) mapping. Of these procedures, 22 (46%), 15 (31%), and 11 (23%) resulted in elimination of all inducible VTs, clinical VT but not all, and none of the inducible VTs, respectively. Forty (85%) procedures were followed by recurrence. The cumulative VT recurrence-free survival was 75%, 50%, and 25% after 1.5, 5, and 14 months, respectively. The cumulative VT recurrence-free survival did not differ by procedural success, mapping technique, or repetition of procedures. There was 1 procedure-related death. CONCLUSIONS: Our study shows a high rate of recurrence in ARVD/C patients undergoing RFA of VT. This likely reflects the fact that ARVD/C is a diffuse cardiomyopathy with progressively evolving electrical substrate. Further studies are needed to define the precise role of RFA of VT in ARVD/C.