Inclusion criteria  At least 18 years old Indicated for de novo or replacement ICD procedure  Exclusion criteria  NYHA IV functional class BMI ≥ 35 kg/m2 Inotropic therapy in past 180 days Subjects with a hemodynamically unstable intrinsic heart rate that requires continual ventricular pacing Presence or planned use of subcutaneous coils/arrays, epicardial patches or epicardial pace/sense leads Subjects on anticoagulation/antiplatelet therapy that cannot be temporarily discontinued for the procedure Logistical or safety related circumstances that may prevent data collection or follow-up Participation in any concurrent clinical study without prior written approval from the Sponsor  Inability to give an informed consent to participate in the Study  Known prior history for any of the following:  Structural abnormalities of the heart that may increase risk of the study procedure or an obstructed/restricted pathway into the mediastinum for the EV-ICD Dilator, EV-ICD Delivery Tool and EV-ICD Lead as assessed from available CT or Echocardiography. Uncontrolled paroxsymal, persistent or permanent atrial fibrillation Median or partial sternotomy Surgery with disruption of the lung, pericardium or connective tissue between the sternum and pericardium Significant anatomic derangement of or within the thorax (e.g., pectus excavatum, significant scoliosis) Thoracic radiation therapy, pneumothorax, pneumomediastinum or other medical treatments/conditions which may complicate the EV-ICD Lead insertion procedure Pericardial disease, pericarditis and mediastinitis Medical treatments, surgeries or conditions that increase the potential for pericardial adhesions FEV1 < 1.0 Liter Surgically corrected congenital heart disease (not including catheter-based procedures) Allergies to the device materials as listed in the Instructions for Use (IFU)