Patent ID: 7403817

Claim:
A pacemaker, comprising: an atrial channel to detect atrial senses corresponding to atrial depolarizations and deliver pacing pulses to an atrium; a ventricular channel to detect ventricular senses corresponding to ventricular depolarizations and deliver ventricular pacing pulses to a ventricle; and a processor circuit coupled to the atrial channel and the ventricular channel, the processor circuit programmed such that the pacemaker operates in a demand pacing mode using an atrial escape interval (AEI); wherein the processor circuit is programmed to set the AEI to a hysteretic AEI value whenever an atrial sense is detected; wherein the processor circuit is programmed to set the AEI to a normal AEI value whenever an atrial pace is delivered, the normal AEI value being less than the hysteretic AEI value; and, wherein the processor circuit is programmed to set the AEI to the normal AEI value when a programmable number of ventricular senses not immediately preceded by an atrial sense or pace is detected.