Cardiac stimulation by means of implanted pacemakers has become widely accepted in the management of heart block. Transvenous endocardial pacemakers, first introduced for temporary cardiac pacing, have largely replaced epicardial pacemakers for permanent cardiac pacing. While implantation of permanent transvenous pacemakers is relatively safe and simple, the procedure is attended by a number of early and late complications, including hematoma, sepsis, perforation of the myocardium, venous obstruction, electrode rejection, fracture of the electrode catheter, and incarceration of the electrode. During attempts to replace a fractured electrode catheter, it is sometimes found that the catheter cannot be withdrawn from the heart. Under such circumstances, it is generally considered safe to leave the old electrode catheter in situ and insert a new electrode. The present case illustrates a complication of this practice which has not been reported previously.
A 71-year-old patient underwent implantation of a fixed-rate transvenous pacemaker in