A leadless intra-cardiac medical device is configured to be implanted entirely within a heart of a patient. The device includes an intra-cardiac extension and a housing. The intra-cardiac extension includes a loop body having at least one loop segment retaining at least one coil group that is configured to one or both of receive and transmit radio frequency (RF) energy, wherein the loop body is configured to extend into a first chamber of the heart. The housing is in electrical communication within the loop body, and includes a transceiver, control logic and an energy source. The housing is configured to be securely attached to an interior wall portion of a second chamber of the heart, wherein the transceiver is configured to communicate with an external device through the RF energy.