Abstract: The invention relates to a defibrillator system having means for transferring electrical energy coupled to tranvenously implantable cardiac leads and methods for transvenous implantation. The cardiac lead has an elongated first member having a tip on one end thereof, an implantable object coupled to the first member, such as a defibrillator electrode, expandable from a collapsed position to an extended position generally away from the lead and means for expanding the object from the collapsed position to the extended position. The transvenous implantation method of the present invention involves entering a vein of a patient, translating through the vein to the patient's cardium atrium, puncturing the atrial lateral wall and forming a hole therein, exiting the atrium through the hole to the pericardial space and inserting the object into the pericardial space.