[Clinical experiences and experimental studies of false sensing with demand pacemakers (author's transl)].

False triggering with a ventricular triggered pacemaker and false inhibition with a ventricular inhibited pacemaker were observed in two patients with complete heart block. These arrhythmias were considered to be attributable to false sensing with a demand pacemaker. Both in vitro and in vivo studies were performed to elucidate the mechanism of these false sensings, and the false sensings were reproduced in a series of experiments. Loose contact of the tip of electrodes to myocardial tissue, refractory period, the distance between two electrodes, and the after potential and its dv/dt of pacemaker impulses are considered to affect the performance of demand pacers.