Pacing parameters may be adjusted to increase the cardiac output of a patient's heart while a patient is awake and/or active and the demand placed on the heart may be greatest, and to decrease or hemodynamic efficiency while a patient is at rest so that the heart itself has time to rest before the next period of higher demand for efficiency begins. This may aid in lessening the strain placed on the heart by making the heart work hard when needed such as when the patient is active, and by permitting the heart to “rest” when the patient is relatively inactive.
