Patent ID: 8626287

Claim:
An implantable medical device comprising: an energy storage device configured to store electrical energy for delivery of a defibrillation therapy to a heart; a plurality of electrodes; a switching circuit configured to connect the plurality of electrodes to the energy storage device; a memory storing a plurality of initial therapy configurations and transition data associated with each one of the plurality of initial therapy configurations, the transition data comprising a second therapy configuration and a third therapy configuration for each one of the plurality of initial therapy configurations, each of the plurality of initial therapy configurations and the associated second and third therapy configurations individually defining a set of the plurality of electrodes and a waveform for delivering the defibrillation therapy; and a processing module configured to: control the switching circuit to deliver the defibrillation therapy using a first one of the initial therapy configurations comprising a first set of the plurality of electrodes and using a biphasic waveform that includes first and second phases; detect a short circuit fault during the biphasic waveform; determine which one of the first phase and the second phase of the biphasic waveform the short circuit fault is detected in; and responsive to detecting the short circuit fault during the first one of the initial therapy configurations, select one of the second therapy configuration and the third therapy configuration according to the transition data associated with the first one of the initial therapy configurations for delivery of a subsequent defibrillation therapy, the second therapy configuration being selected if the short circuit fault is detected during the first phase, the third therapy configuration being selected if the short circuit fault is detected during the second phase, the second therapy configuration being different than the first one of the initial therapy configurations and comprising a second set of the plurality of electrodes and one of a biphasic or monophasic waveform.