Stepwise Approach To sUbstrate Modification for Ventricular Tachycardia (STRATUM VT)

The goal of this trial is to test the impact of a step-wise approach for catheter ablation of recurrent ventricular tachycardia, (irregular heart rhythms that originate in the bottom chambers of the heart), in patients with a previous heart attack for whom catheter ablation is clinically indicated.

Sudden cardiac death due to VT (ventricular tachycardia) or VF (ventricular fibrillation) occurs at an estimated rate of 300,000 events per year in United States, accounting for 5.6% of annual mortality22. A significant proportion of patients treated with ICDs (implantable defibrillators) will receive shocks due to recurrent VT, resulting in increased mortality8. As a result, catheter-based ablation has emerged as an effective treatment for recurrent VT. However, no study has assessed the impact of a step-wise approach on the outcome of catheter ablation of VT. The investigators propose a prospective, multicenter, non-randomized, single-arm trial to evaluate the impact of a step-wise approach to catheter ablation on ventricular tachycardia recurrence. Given the increasing use of catheter ablation in patients with recurrent ventricular tachycardia, this study will answer a critical question regarding the impact of a step-wise approach on the inducibility of VT at the end of the procedure and clinical recurrences of ventricular arrhythmias at 6 months.

specific electrophysiological and mapping techniques of activation and entrainment mapping during ongoing VT. Substrate mapping and ablation (substrate modification.) catheter ablation - a medical procedure used to treat some types of arrhythmia

The procedural efficacy as defined as acute success of a standardized step-wise approach for substrate-based catheter ablation of recurrent ventricular tachycardia in patients with coronary artery disease and prior ventricular tachycardia or appropriate therapy. Acute success will be defined as the ability to render VT non-inducible with a standardized complete stimulation protocol. catheter ablation - a medical procedure used to treat some types of arrhythmia

Chronic success will be defined as no recurrence of sustained VT or VT resulting in ICD therapies (ATP and/or ICD shocks) at 6 months follow-up as compared to baseline.

2) Procedural safety as defined by the number of complication within 1week associated with the procedure.

Inclusion Criteria: Age 18 to 90 years. History of coronary artery disease. Presence of, or planned for, an ICD prior to discharge. Presentation for management of ICD shock/ATP therapy or monomorphic ventricular tachycardia. Exclusion Criteria: Ventricular arrhythmia not thought to be due to CAD. Unstable angina CVA within 30 days. Protruding left ventricular thrombus or critical aortic stenosis on pre-ablation echocardiography Pregnancy Any condition resulting in an absolute contraindication to anticoagulation Inability to follow-up at ICD clinic. Inability to give informed consent. Non-inducible for sustained monomorphic ventricular tachycardia. Prior substrate guided ablation. Definite need for epicardial ablation, as determined by the primary operator.