LONGEVITY Study. Evaluation of the Device and Battery Longevity of Boston Scientific Market-released ICD and CRT-D Devices

Inclusion Criteria: * Subject has been implanted within 30 days with a commercially available Boston Scientific ICD or a CRT-D device according to current guidelines and/or center's current practice * Subject is willing and capable (or appropriate legal representative is willing and capable) of authorizing access to and use of health information as required by an Institution's Institutional Review Board (IRB), Research Ethics Board (REB) or Ethics Committee (EC) * Is willing and capable (or appropriate legal representative is willing and capable) of providing authorization/consent for participation in the study. Exclusion Criteria: * Subject is unable or unwilling to comply with the study protocol requirements * Subject is under the legal age for signing study consent in accordance with state or national law * Subject has a life expectancy of less than twelve months * Women of childbearing potential who are or might be pregnant at the time of study enrollment (method of assessment upon physician's discretion) * Subject on active heart transplant list * Subject with any prior pulse generator infection or lead infection which is either systemic or localized * Subject received a commercially available Boston Scientific ICD or CRT-D device with a battery capacity of 1.5 amp/hour or less * Subject implanted with Boston Scientific's subcutaneous implantable defibrillator system (s-ICD) or has a lead that is under recall/advisory at the time of enrollment