Unpinning Termination Therapy for VT (US)

Inclusion Criteria: The subject must meet all of the following inclusion criteria: 1. Life expectancy of 1 year or greater 2. Male or female between 18 and 80 years of age 3. Willing and able to comply with the study protocol, provide a written informed consent 4. Indication for an endocardial VT catheter ablation for symptomatic VT with use of CESS V1.0 or CESS V1.1 OR an indication for an ICD procedure (de novo implant, replacement or upgrade) or de novo CRTD procedure for the risk of or presence of VT (CESS 1.0 and 1.1) 5. Etiology of arrhythmia, or risk of arrhythmia being ischemic cardiomyopathy or non-ischemic cardiomyopathy 6. Medically stable at time of consent to undergo DFT testing performed under general anesthesia or conscious sedation as determined by the investigator Exclusion Criteria: The subject must not meet any of the following exclusion criteria: 1. Medically unstable at time of study and unsafe to undergo DFT testing under general anesthesia or conscious sedation as determined by the investigator 2. Hemodynamic instability as determined by the investigator 3. AF or atrial flutter at time of Study Procedure and no anticoagulation for preceding 3 weeks and no preoperative transesophageal echocardiographic, Cardiac CT or Intracardiac echocardiographic confirmation of the absence of LA thrombus 4. Presence of intracardiac thrombus 5. Inability to pass catheters to heart due to vascular limitations 6. Cardiovascular anatomical defects that would complicate placement of the lead or catheter required by the protocol, including congenital heart disease and cardiac vein anomalies as determined by the investigator 7. Pregnancy confirmed by test within 7 days of procedure 8. Presence of a chronically implanted lead in the CS 9. Presence of a ventricular assist device, including intra-aortic balloon pump 10. Subjects indicated for VT ablation and experiencing VF 11. Subjects requiring the use of inotropes and/or vasopressors for hemodynamic support within the 3 days prior to the study 12. Prior VT catheter ablation with associated hemodynamic compromise despite pressor agents or stroke 13. Incessant VT/VF or VT/VF storm within six months of scheduled procedure 14. LVEF \< 20% 15. New York Heart Association (NYHA) Class IV heart failure 16. Planned epicardial VT ablation on the same day as the research study 17. History of hyper-coagulable state that could increase risk of thromboembolic events 18. History of hemodynamic compromise due to valvular heart disease requiring IV inotropes or other circulatory support 19. Unstable coronary artery disease as determined by the investigator 20. Severe proximal three-vessel or left main coronary artery disease, without revascularization as determined by the investigators 21. History of embolic stroke, Transient Ischemic Attack or other thromboembolic event in the past 6 months 22. History of Hypertrophic Cardiomyopathy, Arrhythmogenic Right Ventricular Dysplasia, Congenital Heart Anomaly, Cardiac Amyloidosis, Genetic Cardiac Channelopathy or Cardiac Sarcoidosis 23. Cardiovascular surgery or intervention within 1 month prior to enrollment or planned for up to 1 month after enrollment (other than the planned treatment procedure) 24. Morbid obesity: BMI\>39 kg/m2 25. Cognitive or mental health status that would interfere with study participation and proper informed consent 26. Presence of mechanical tricuspid valve 27. Active Endocarditis 28. Ventricular arrhythmia with etiology of sarcoid flare 29. Previously implanted lead is under recall by manufacturer or evidence of lead failure as determined by the investigator 30. End Stage Renal Disease on hemodialysis or peritoneal dialysis, or creatinine clearance \<15 ml/min 31. Any other medical condition which may affect the outcome of this study or safety of the subject as determined by the investigator