Patent ID: 7551961

Claim:
An implantable cardiac stimulation device comprising: an atrial pulse generator that provides atrial pacing pulses; a premature ventricular complex detector that detects premature ventricular complexes of the heart; a sensing circuit that senses atrial events; and a P wave discriminator that identifies an atrial event sensed by the sensing circuit following detection of a premature ventricular complex as one of a retrograde P wave and a normal sinus P wave, the atrial pulse generator being adapted to deliver an atrial pacing pulse responsive to the discriminator identifying an atrial event sensed by the sensing circuit following detection of a premature ventricular complex as a retrograde P wave and an inhibit circuit that inhibits the atrial pulse generator from providing an atrial pacing pulse responsive to the discriminator failing to identify an atrial event sensed by the sensing circuit following detection of a premature ventricular complex as a retrograde P wave.