US Patent 7684870 Direct current fibrillator

An implantable cardiac device to induce fibrillation in the heart of a patient to allow testing of the defibrillation capability of the device. The device induces fibrillation using a direct current across the heart. The shock to the heart may be applied in a method to minimize discomfort to the patient. The heart is monitored during application of the shock. The voltage of shock at the heart is gradually increased until fibrillation is induced. Once the fibrillation is detected the shock may be stopped. This results in a minimized voltage level and duration for the shock to the heart, thereby diminishing pain and discomfort to the patient.