Abstract: Housings for implantable medical devices are configured so as to engage with surrounding tissues inside of a body and resist both rotation in place and movement through the body. Device housings include shapes, surface features, and/or standard surfaces and may include attached implements that engage the surrounding tissue. Shapes include elongated members, flared ends, and so forth. Surface features include pores, grooves, through-holes, and so forth. Attached implements include needles, barbs, tension springs, and so forth. Also provided are methods for engaging an implantable medical device with surrounding tissues.

Abstract: Cardiac devices employing an active can and/or electrode assembly with dedicated defibrillation and sensing electrodes. A housing is configured for subcutaneous non-intrathoracic placement in a patient, the housing having a first face and a second face. One of the first and second face is directed away from the patient's heart, and the other of the first and second face is directed towards the patient's heart. A cardiac arrhythmia may be sensed using an electrode assembly positioned in or on the first face of the housing. A cardiac defibrillation therapy may be delivered to the patient's heart using an electrode assembly positioned in or on the second face of the housing in response to the detected arrhythmia.