SERF VT Ablation Early Feasibility Study (EFS)

Inclusion Criteria: 1. Subject has sustained, monomorphic VT 2. Subject has recurrent, symptomatic VT 3. Subject has drug refractory or drug intolerant sustained VT following use of at least one Class III antiarrhythmic as demonstrated by a recurrent arrhythmia and is not a suitable candidate per the investigator's expert opinion for ongoing or alternative drug therapy 4. ECG and/or ICD evidence of a spontaneous VT recurrence within the prior 6 months that is suspected to be the same VT as initially targeted in a prior ablation 5. Subject has minimum 3-month ICD interrogation history available for evaluation 6. Subject has LVEF \> 20%, confirmed by echo or comparable technique during baseline evaluation 7. Subject is at least 18 years old 8. Subject has signed the informed consent, and is willing and able to participate in all study procedures and follow up requirements EXCLUSION CRITERIA: 1. Subjects with VT of idiopathic origin 2. Subjects with VT with ECG or MRI/CT findings suggestive of right ventricular free wall origin 3. Subjects with VTs of septal origin require special care to minimize the risk of heart block, particularly within 2 cm of the AV node/proximal conduction system; Subjects requiring ablation at such locations should only be included when the arrhythmia itself is life-threatening or otherwise sufficiently severe to justify the risk 4. Subject with myocardial infarction (MI) or unstable angina within previous 60 days 5. Subject with cardiac surgery or percutaneous coronary intervention (PCI) within previous 60 days 6. Subject with class IV (NYHA) heart failure 7. Subject with prosthetic cardiac valve(s), severe aortic stenosis or flail mitral valve 8. Subject with left ventricular assist device planned or required for the procedure 9. Subjects with co-morbidities such that they have less than 1-year life expectancy 10. Subject with evidence of intracardiac and/or laminated thrombus (in the left atrium including left atrial appendage or the left ventricle) evident by cardiac CT or transesophageal echo (TEE) and transthoracic echo (TTE) (with contrast if indicated) within 48 hours prior to ablation procedure 11. Subject with thrombocytopenia or other coagulopathy 12. Women who are or may potentially be pregnant (must be post-menopausal or have a negative pregnancy test) 13. Subject with other acute illness or active systemic infection (unrelated to VT or its origin) 14. Significant congenital heart disease or cardiac anomaly 15. Allergy or contraindications to the medications/agents used during a standard ablation/EP intervention. 16. Subject concurrently enrolled in any other investigational drug or device study that the investigator deems would interfere with study results