A leadless cardiac pacemaker comprises a housing, a plurality of electrodes coupled to an outer surface of the housing, and a pulse delivery system hermetically contained within the housing and electrically coupled to the electrode plurality, the pulse delivery system configured for sourcing energy internal to the housing, generating and delivering electrical pulses to the electrode plurality. Systems and methods for delivering the leadless cardiac pacemaker with delivery catheters are also provided. In some embodiments, the delivery catheters include first and second coaxial shafts configured to apply rotational torque to the pacemaker. In other embodiments, the pacemaker is held in place on the catheter with a tether.