D2-EPG Study: Evaluation of New Sensing Circuitry and Capture Management

Inclusion Criteria: * Patients who are scheduled for implantation or replacement of an implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) device * Patients must have or receive Medtronic transvenous atrial and ventricular leads in association with the scheduled device implant or replacement. Exclusion Criteria: * Patients who have 3rd degree heart block, as assessed by the investigator * Patients who have a mechanical tricuspid heart valve * Patients who have received an investigational new drug or device, or are currently enrolled in a clinical study for a new indication of an approved drug or device