IMPLANTABLE HEART STIMULATOR FOR ENABLING NORMAL ATRIO-VENTRICULAR STIMULATION SEQUENCE IN THE PRESENCE OF AV-NODAL INTERFERENCE

摘要

Heart stimulator (2) for enhancing cardiac performance of a patient suffering from ventricular rhythms tending to overdrive the atrial rhythm The heart stimulator comprises atrial sensing means (6) for sensing P-waves associated with atrial contractions, ventricular sensing means (10) for sensing R-waves associated with ventricular contractions and atrial stimulating means (4) for generating and applying stimulation pulses to the atrium. The heart stimulator further comprises timing means (14) for generating a detection window having a predetermined length for said ventricular sensing means, said detection window starts upon detection of an atrial event (A), intrinsic or stimulated. If an R-wave is sensed by the ventricular sensing means during the window a focus that pre-depolarizes the ventricles is considered to exist, wherein the atrial stimulation rate is increased for a preset number of consecutive heart cycles.