T-wave oversensing after implantation of pacemakers with automatic sensitivity adjustment in patients with atrioventricular block.

T-wave oversensing in pacemakers is rare because the set sensitivity is generally fixed. However, several models of pacemaker employ automatic sensitivity adjustment. Here, we present two cases of atrioventricular block treated by implantation of the pacemaker with automatic sensitivity adjustment. After implanting the pacemaker with automatic sensitivity adjustment, ventricular pacing suppression due to T-wave oversensing occurred. In both cases, T-wave oversensing disappeared after adjusting the setting sensitivity from 0.9 to 2.0 mV.