An implantable cardiac device is programmed to promote intrinsic rhythm of a patient's heart to alleviate orthostatic hypotension. In one implementation, the cardiac device is set in a reduced rate mode while the patient is in a less upright position, such as when resting in a supine position. If the patient is in intrinsic rhythm when transitioning to a more upright position, the cardiac device disables administration of any increased pacing rate for a programmed duration. In this manner, the patient will experience a more natural variation in heart rate during transition from the less upright posture to the more upright posture (e.g., from supine to sitting or standing). On the other hand, if the patient is being paced during the transition, the cardiac device administers an increased base rate or triggers an orthostatic response algorithm.