Patent ID: 7986993
Filing Date: 2011-07-26
Classification: A61N

Abstract:
1. An implantable cardiac stimulation system comprising: a pulse generator that provides atrial and ventricular pacing stimulation pulses on demand, the pulse generator further providing an AV interval; an AV hysteresis circuit that extends the AV interval from a base AV interval to an extended AV interval to promote intrinsic heart activity; a refractory circuit that establishes a PVARP following each provided ventricular pacing pulse including a lengthened PVARP longer in duration than a normal PVARP responsive to the AV hysteresis circuit extending the AV interval from the base AV interval to the extended AV interval; and a sensing circuit that senses retrograde P waves occurring during an extended PVARP; wherein the AV hysteresis circuit restores the AV interval to the base AV interval in response to the sensing circuit sensing a retrograde P wave during an extended PVARP and the AV refractory circuit restores the PVARP to the normal PVARP in response to the AV hysteresis circuit restoring the AV interval to the base AV interval.