Clinical Research Directory

Inclusion Criteria: 1. Patients with two or more documented spontaneous episodes of sustained symptomatic VT within 3 months or 1 sustained episode of VT or VT storm (two or more VTs in 24 hours) which required device therapy (shock or anti-tachycardia pacing), external cardioversion, escalated antiarrhythmic therapy, and / or hospitalization * Documented episodes assessment will be performed by a review of ECGs, hospitalization records, and/or Implantable Cardioverter Defibrillator (ICD) interrogation * Patients must have an ICD implanted 2. Age ≥18 years 3. LVEF ≥ 30% as estimated by echocardiography, contrast ventriculography, radionuclide imaging or cardiac magnetic resonance imaging within the previous 30 days. 4. Willing and capable of understanding the objective, risk, and requirement of the study, and providing consent. 5. Able and willing to comply with all pre-, post- and follow-up testing and requirements. Exclusion Criteria: 1. Definite protruding LV thrombus on pre-ablation imaging. 2. Myocardial infarction (MI) within the preceding 2 months. Patients with incessant VT (present 50% of the time with intervention for a period \>12 hrs) may be enrolled if their MI is at least 3 weeks old. 3. Absence of vascular access to the heart chambers. 4. Other disease process likely to limit survival to less than 6 months. 5. Class IV heart failure. 6. Serum creatinine of ≥ 2.5 mg/dl (221 umol/L). 7. Thrombocytopenia (\< 50 x 109/L) or coagulopathy. 8. Contraindication to heparin. 9. Women who are pregnant. 10. Cardiac surgery (i.e. ventriculotomy, atriotomy) within the past 2 months. Patients with incessant VT may be enrolled if their surgery is at least 3 weeks old. 11. Acute illness or active systemic infection. 12. Severe aortic stenosis or flail mitral valve. 13. Uncontrolled heart failure. 14. Significant congenital anomaly or medical problem that in the opinion of the principal Investigator would preclude enrollment in the study. 15. Enrolled in an investigational study evaluating another device or drug. 16. Unwilling to participate in the study or unavailable for follow up visits. 17. Previous VT ablation within a year. 18. Epicardial mapping or ablation is anticipated or planned before the VT ablation procedure.