Implantable Heart Stimulator for Enabling Normal Atrio-Ventricular Stimulation Sequence in the Presence of Av-Nodal Interference

摘要

A heart stimulator for enhancing cardiac performance of a patient suffering from ventricular rhythms that tend to overdrive the patient's atrial rhythm, has sensing circuitry that detects atrial events and ventricular events, and an atrial stimulator that generates and supplies stimulation pulses to the atrium. A timer generates a detection window having a predetermined duration for the ventricular sensing, the detection window starting upon detection of an intrinsic or stimulated atrial event. If an R-wave is sensed from the ventricle during the detection window, a control unit determines that a focus, that pre-depolarizes the ventricles, exists, and the control unit operates the atrial stimulator to increase the atrial stimulation rate for a predetermined number of consecutive heart cycles.