Porous electrodes were designed and implanted to optimize sensing and pacing performance of the cardiac pacemaker. These electrodes were manufactured to create an effective, atraumatic endocardial interface in order to (1) decrease chronic stimulation thresholds and pacemaker current drain; (2) facilitate fibrous protein tissue ingrowth for reduced electrode displacement; and (3) to create a large electrolytic surface area of contact for reduced polarization voltage, thus improving impulse and electrogram transmission. Thus far, clinical results demonstrate reduced long-term threshold and decreased current drain. Long-term advantages of porous electrodes remain to be determined.