The purpose of this study is to test specific device programming in patients without a previous history of a life-threatening, abnormally fast heartbeat who are implanted with a Medtronic ICD (Implantable Cardioconverter Defibrillator) or ICD with CRT (Cardiac Resynchronozation Therapy) device. The information learned from this study could be used to guide physicians in future ICD or CRT device programming.