Device eccentricity: postmagnet behavior of DDDR pacemakers with automatic threshold tracking

The normal pacing system function associated with the AutoCapture Pacing System algorithm triggered concern on the part of the clinical staff caring for the patient when the initiation of a threshold search sequence was detected during a transtelephonic follow-up evaluation. The analysis of the rhythm demonstrates that the behavior of the system is normal and consistent with the design of the AutoCapture algorithm. As a variety of new algorithms are introduced, similar unexpected but normal behaviors can be anticipated.