A leadless pacing device may include a housing having a proximal end and a distal end, and a set of one or more electrodes supported by the housing. The housing may include a first a distal extension extending distally from the distal end thereof. The distal extension may include a retractable and/or rotatable distal electrode. The distal electrode may be configured to be delivered to and pace at the Bundle of His. The leadless pacing device may be releasably coupled to an expandable anchor mechanism.