The present invention includes a method for controlling pacemaker therapy in a patient with an implanted biological pacemaker. The method may include pacing a heart at a predetermined rate using an electronic pacemaker and configuring the pacemaker to periodically enter a biological pacemaker weaning mode. The weaning mode may include ceasing pacing for at least a predetermined length of time and monitoring the heart to detect electrical depolarizations of a ventricle of the heart during the predetermined length of time. The weaning mode may further include determining the length of time between the cessation of pacing and the detected electrical depolarization and determining if the length of time between the cessation of pacing and the detected electrical depolarization is less than a maximum predetermined interval. The pacemaker therapy may be withheld as long as the length of time is less than the maximum predetermined interval. Further, if the length of time exceeds a maximum interval, the pacemaker will exit the weaning mode.
