An implantable cardiac stimulation device controls dynamic atrial overdrive pacing based, in part, on sensor indicated rate. In one example, the stimulation device adjusts an overdrive pacing rate based on the sensor indicated rate by periodically decreasing the overdrive pacing rate by a programmed rate decrement whenever a difference between the current overdrive pacing rate and the sensor indicated rate falls outside predetermined acceptable range while the sensor indicated rate is decreasing. The overdrive pacing rate is decreased in this manner until a) the overdrive pacing rate falls below the base rate, rest rate or the sensor indicated rate or until b) an event triggers an increase in the overdrive pacing rate, such as the appearance of intrinsic breakthrough heart beats. The overdrive pacing rate is not decreased if the sensor indicated rate is increasing or stable. With this process, the overdrive pacing rate is controlled to typically remain slightly above the intrinsic rate without being constrained by a preprogrammed number of pacing cycles. Hence, the overdrive pacing rate can be made to closely track the intrinsic rate regardless of whether the intrinsic rate is changing rapidly or is fairly stable.