Parasternal Extravascular ICD System Pivotal Clinical Investigation (ALARION EV) Study

Inclusion Criteria

• At least 18 years old
• Class I or IIa indication for implantation of an ICD according to the ACC/AHA/HRS Guidelines or ESC guidelines

Exclusion Criteria

• Patients who cannot read or write
• Expected survival \< 1 year
• Pregnant or nursing subjects and those who plan pregnancy during the clinical investigation follow-up period
• Participation in any concurrent clinical study without prior approval from the Sponsor
• Inability or unwillingness to provide informed consent to participate in the study
• Any known circumstances which may prevent the completion of protocol testing and data collection through the 6-month follow-up visit
• Circumstances that may prevent data collection or completion of specified follow-up visits
• Allergies to any device materials listed in the Instructions for Use (IFU)
• Contraindication for temporary suspension of oral/systemic anticoagulation
• Known history of lung disease with FEV1 \< 1.0 Liter

Device Related

• Implanted with or planned implantation of any device which delivers current in the body that may interfere with therapy delivery, including, but not limited to a pacemaker, LVAD or neurostimulator
• Implanted with a subcutaneous ICD lead, subcutaneous coils/arrays, epicardial patches or epicardial pace/sense leads
• Any known need for MRI prior to approval of MRI conditional labeling

Anatomy Related

• Known structural abnormalities of the heart that may increase risk of the Parasternal EV-ICD System procedure
• Known obstructed or restricted pathway into the mediastinum for the Atala™ lead
• Prior surgery with disruption of the lung, pericardium or connective tissue between the sternum and pericardium, including sternotomy of any type
• Known significant anatomic derangement of or within the thorax (e.g., pectus excavatum, significant scoliosis)
• History of thoracic radiation therapy or other medical treatments/conditions which may complicate the Parasternal EV-ICD System implant procedure
• Known adhesions in the thorax or history of medical treatments, surgeries or conditions that increase the potential for adhesions in the thorax
• Surgically corrected congenital heart disease (not including catheter-based procedures)

Cardiac Related

• Indication for permanent bradycardia pacing or cardiac resynchronization therapy
• Decompensated heart failure
• Currently on inotropic therapy
• Known history of pericardial disease, pericarditis or mediastinitis
• Risk factors associated with defibrillation testing:

• Severe aortic stenosis
• Current Intracardiac LA or LV thrombus
• Severe proximal three-vessel or left main coronary artery disease without revascularization
• Hemodynamic instability
• Unstable angina
• Recent stroke or transient ischemic attack (within the last 3 months)
• Known inadequate external defibrillation
• LVEF \< 20% (most recent assessment; must be within 180 days of consent)
• LVEDD >70 mm (most recent assessment; must be within 180 days of consent)