Electrocardiographic diagnosis of pacemaker catheter displacement.

C atheter displacement is an infrequent but bothersome cause of failure of implanted pacemaker systems. The prevalence of catheter displacement is 6r to 45 per cent2 of all permanent transvenous catheter implantations. Displacement can occur at any time, but is most common within the first month, and has occurred as many as 24 months after implantation.1 Marked catheter displacement usually results in intermittent or total failure of pacing, with return of the symptoms experienced before artificial pacing. Occasionally, catheter movement does not result in loss of pacing, and there may be no sign or symptom to indicate the problem. This is a report of the use of the electrocardiogram (ECG) pacemaker stimulus artifact to detect catheter movement. Plotting of the frontal and horizontal plane vector of the stimulus artifact, derived from a standard twelve lead ECG, usually gives enough information to detect gross catheter tip movement.