A leadless cardiac pacemaker is adapted for implantation into triangle of Koch or His bundle with a plurality of individual electrodes spread in the vicinity of implantation site. Individual electrodes are first evaluated for their suitability for sensing and pacing of atrial and ventricular chambers of the heart. Individual electrodes are then selected for delivery of cardiac pacing to multiple heart chambers from a single intra-cardiac location. Remaining non-selected individual electrodes may be abandoned. Also described is an adapter with multiple electrodes configured to dock with a conventional leadless or standard pacemaker to operate in the same way.
