A system is provided, comprising: a sensor adapted to detect a predetermined cardiac activity indicated for a defibrillation shock a vagal nerve stimulator adapted to deliver vagal nerve stimulation and a defibrillator adapted to subcutaneously deliver the defibrillation shock. Vagal nerve stimulation (102) may be provided to lower a defibrillation threshold (DFT) in preparation for the defibrillation shock. Various embodiments apply prophylactic vagal nerve stimulation (104) either in addition to the nerve stimulation therapy to lower DFT, or as a therapy without the nerve stimulation therapy to lower DFT.
