This study will be conducted at up to 8 sites and will randomize 50 patients over 1 year to a strategy of catheter ablation (n=25) vs. state-of-the-art pharmacologic therapy (n=25). To be considered for enrollment in this pilot trial, patients must be at least 18 years of age and must have an ICD for a primary or secondary prevention indication, have ≥ 1 documented ICD shock or ≥ 3 ATP therapies for VT in the absence of a reversible cause that in the opinion of the treating physician requires further therapy and be eligible for both catheter ablation and at least 1 antiarrhythmic medication. Patients will be followed at 3 and 6 months and their vital status will be determined via a phone call at 12 months. Data on the safety and efficacy of therapies used in the pilot study will be collected. Of particular interest are adverse events resulting from the catheter ablation procedure and major side effects from antiarrhythmic medications.