Automatic functions in cardiac pacing: optimization of device and patient therapy

An overview of advances is presented. The focus is on automatic functions that have been developed to monitor the patient continuously and readjust the postventricular atrial refractory period, the atrioventricular (AV) delay, the ventricular refractory period, and the pacemaker stimulus intensity. The advent of automatic algorithms for the postventricular atrial refractory period may have broadened considerably the clinical application of dual chamber pacemakers. Automatic adjustment of the ventricular refractory period has been demonstrated in an implantable pacemaker and may eliminate the rhythm disturbance associated with inappropriate T-wave sensing. Automatic adjustment of the AV delay has been implemented, and there is evidence suggesting that improved hemodynamics may result. Automatic output regulation has emerged in an implantable pacemaker and promises to increase device longevity while providing important patient safety benefits.