Inappropriate pacing due to autoperpetuation of the ventricular rate stabilization algorithm: A manifestation of T wave oversensing by ICDs

Preventive pacing algorithms designed to eliminate the pause that follows a premature ventricular depolarization have been incorporated in current imp lantable defibrillators. We report a patient in whom intermittent T wave ov ersensing frequently invoked the ventricular rate stabilization algorithm a nd resulted in periods of inappropriate VVI pacing. The problem was solved by decreasing the maximum sensitivity from 0.3 mV to 0.45 mV. Implant testi ng had revealed adequate sensing of ventricular fibrillation with a maximum sensitivity of 1.2 mV.