An intra-cardiac implantable medical device (IIMD) system may include a housing and an intra-cardiac (IC) device extension. The housing may be configured to be implanted entirely within a local chamber of the heart. The housing includes a base configured to be secured to the local chamber. The IC device extension may include a proximal end, a distal end, and an extension body extending there between. The proximal end may be coupled to the housing and configured to be located in the local chamber. The extension body may include an IE orientation segment connected to a chamber transition segment that is sufficient in length to extend from the local chamber into an adjacent chamber. The IE orientation segment is configured to be lodged within the adjacent chamber in order to stabilize the system within heart.