Patent ID: 7020518

Claim:
An implantable system for the defibrillation or cardioversion of a patient's heart, said system comprising: first and second defibrillation electrodes configured for positioning in operable association with the heart of the subject, said first and second defibrillation electrodes when so positioned defining a gradient field in the heart between said first and second electrodes and in a region to be defibrillated; a third defibrillation electrode configured for positioning in the gradient field between said first and second electrodes; a pulse generator operatively associated with said first, second and third defibrillation electrodes and configured for concurrently delivering (a) a first defibrillation pulse between said first and third electrode and (b) a second defibrillation pulse between said second and third electrodes, with the voltage for each of said first and second defibrillation pulses being less than the voltage for a single defibrillation pulse delivered between said first and second electrodes; and first and second transveneous catheters, wherein said first, second and third electrodes are carried by one of said first and second transveneous catheters, and wherein said first transveneous catheter is fixed to said second transveneous catheter.