The therapy controller may modify the cardiac pacing therapy by alter a pacing rate (e.g., change from a normal sleep rate to an overdrive pacing rate), pacing timing (e.g., modify the AV delay or other pacing timing parameter), pacing mode, (e.g., switch from DDD to VVI pacing or from a tracking mode to a non-tracking pacing mode) and/or pacing type (e.g., switch from dual chamber to biventricula