An implantable medical device (IMD) comprises a plurality of deep tines configured to be advanced into a septum of a heart of a patient in different directions that are not parallel to a longitudinal axis of the implantable medical device, wherein each deep tine of the plurality of deep tines is configured to deliver cardiac pacing to cardiac tissue distal to a chamber of the heart in which the IMD is implanted, and one or more shallow electrodes engageable with the septum, wherein the one or more shallow electrodes are configured to deliver cardiac pacing to the chamber of the heart in which the IMD is implanted.