Two chamber - cardiac pacemaker having hysteresis and optical mali ized a - v - delay for the use of a maximum number of natural heart ventricle - cycles.

摘要

A DDD pacemaker including stimulating means to stimulate the ventricles of a heart after a predetermined A-V delay period includes means for adjusting the A-V delay period to enhance the probability of detecting naturally occurring ventricular depolarization signals when such signals are being detected at a predetermined rate and switching to a more hemodynamically appropriate A-V delay period when paced beats predominate. The invention is implemented in software run on a microprogrammable controller comprising the DDD pacemaker.