Patent ID: 7194302

Claim:
A cardiac device comprising: an implantable housing having an external surface; first and second subcutaneous electrodes; at least one lead connecting said housing to at least one of said first and second subcutaneous electrodes; and a cardiac stimulator disposed in said implantable housing, the cardiac stimulator electrically connected to said first and second subcutaneous electrodes and adapted to apply electrical pulses between said first and second subcutaneous electrodes, wherein at least one of said first and second subcutaneous electrodes is formed on the external surface of the housing, said first and second subcutaneous electrodes sized and configured to generate a vector over a substantial portion of the heart of a patient from their subcutaneous positions when said first and second electrodes are implanted at respective first and second subcutaneous positions within the patient, and wherein said first and second electrodes have respective contact surfaces that, in implantation, are in electrical contact with tissues, said contact surfaces providing a combined total surface area of less than 100 cm 2 .