An implantable medical device includes a header configured to be mounted to an end of a device housing that contains an electronics module therein. The header includes an antenna, a sensing electrode, and a header body that at least partially surrounds the antenna and the sensing electrode. The sensing electrode includes a first body portion, a second body portion, and a bridge portion that mechanically and electrically connects the first and second body portions. The first body portion is at least partially exposed to an external environment along a first side of the header, and the second body portion is at least partially exposed to the external environment along a second side of the header that is different from the first side.