Functional ElectroAnatomiC Isochronal Late Activation Mapping for Empiric VT Ablation Trial

This is a multicenter, prospective, parallel, randomized controlled trial to test for non-inferiority with an ILAM-guided VT ablation compared to conventional voltage- based ablation. The study has two treatment arms: conventional voltage mapping and ablation (control arm). In the investigational arm, the ablation strategy is guided by ILAM to target deceleration zones, blinded to voltage mapping. In the control arm, ablation will be performed to extensively ablate all low voltage regions (\

Criteria To participate in this clinical investigation, the subjects must meet all of the following inclusion criteria: 1. Patient is ≥18 years of age. 2. Able and willing to comply with all study requirements. 3. At least one documented episode of sustained MMVT (\>30 sec) by either EGM or ECG (including Holter, or loop recorder) in the 6 months prior to enrollment. 4. Informed of the nature of the study, agreed to its provisions, and has provided written informed consent as approved by the Institutional Review Board/Ethics Committee (IRB/EC) of the respective clinical study site. 5. Refractory (i.e., not effective, not tolerated, or not desired) to at least one anti-arrhythmic medication (including, but not limited to beta blocker, mexiletine, amiodarone or sotalol) for treatment of MMVT. 6. Structural heart disease (ischemic or non-ischemic) with one of the following (a, b or c): 1. Evidence of myocardial scar by echocardiography (segmental wall motion or wall thinning), CT (wall thinning) and/or MRI (presence of delayed enhancement /late gadolinium enhancement) . CT or MRI with scar is mandatory for inclusion of NICM., or 2. Left ventricular ejection fraction (EF) \