1. A medical device system, comprising: a cardiac defibrillator including electronic control circuitry for determining the occurrence of an arrhythmic episode of a heart; a medical device programmer having programmer electronic circuitry coupled to an interactive display screen and the electronic control circuitry of the cardiac defibrillator, where at least one cardiac defibrillator parameter is changed in the medical device programmer, the programmer electronic circuity simulates the effect of the changed cardiac defibrillator parameter using cardiac data received from the cardiac defibrillator, and indicates if appropriately treated arrhythmias would have received treatment and mistakenly treated arrhythmia would have fail to receive treatment under the simulation in the medical device programmer.