Pacing failure due to markedly increased stimulation threshold 2 years after implantation: successful management with oral prednisolone: a case report.

In a 53-year-old male who had undergone transvenous permanent pacing, intracardiac potential reduced progressively over a 2-year period and exit block developed, while the stimulation threshold was markedly increased. After oral prednisolone for 5 months, the stimulation threshold reduced gradually along with an increase in intracardiac potential, culminating in no recurrence of exit block for the ensuing 2 years. The clinical course suggests that progressive reduction in intracardiac potential may have presaged the late development of exit block, and that oral prednisolone may be a therapeutic approach for the restoration of ventricular capture even 2 years after implantation.