Spontaneous secure reimplantation of a dislodged pacemaker electrode onto the right ventricular outflow tract, reestablishing a sufficient pacing condition.

A 62-year-old woman underwent cardiac pacemaker implantation for sick sinus syndrome with bradycardia, and the tip of an endocardial tined lead was positioned to the right ventricular apex. On the fifth postoperative day, an incomplete pacing failure, lasting about 10 min, was observed transiently on 24-h monitoring. This event, however, was not considered to be a clinical manifestation of the ensuing complication until the patient visited our pacemaker clinic 2 months postoperatively. At that time, a chest x-ray demonstrated that the electrode tip had migrated markedly to the right ventricular outflow tract (RVOT), but presented a sufficient pacing condition. The reimplantation site appeared to be very insecure for pacing, raising the potential risk of repeat dislodgement since the lead was not provided with a helix. At the second operation, performed to assess the problem, the ventricular excitation threshold measured at 1.3 V with a 0.5 ms pulse width. Furthermore, it was unexpectedly disclosed that the electrode tip was so tightly anchored at the site that it could not be withdrawn, eliminating the possibility of repeat dislodgment. Consequently, the entire original pacing system could be used as before and no further complications were observed. Although the situation encountered was very rare and seemed to be problematic, careful observation might be an alternative to surgical intervention even when a tined tip without helix has been used.