Protego DF4 Post Approval Registry

Inclusion Criteria: * Implanted within the last 30 days or candidate for implantation of a BIOTRONIK ICD or CRT-D DF4 compatible system along with the Protego DF4 lead * Meets ICD or CRT-D system implant recommendations as defined in guidelines published by relevant professional societies * Able to understand the nature of the registry and provide informed consent * Available for follow-up visits on a regular basis at the investigational site for the expected 5 years of follow-up * Age greater than or equal to 18 years Exclusion Criteria: * Enrolled in any investigational cardiac device trial * Planned cardiac surgical procedures or interventional measures within the next 6 months * Expected to receive heart transplantation or ventricular assist device within 1 year * Life expectancy of less than 1 year * Presence of another life-threatening, underlying illness separate from their cardiac disorder * Patients reporting pregnancy at the time of enrollment