Pacemaker lead malfunction following superior vena cava stenting

A 68-year-old man was seen in consultation for pacemaker malfunction 3 years after implantation. Four months earlier, a metal stent (WALLSTENT® Endoprosthesis: 12 mm × 40 mm) was placed for occlusion of the superior vena cava (SVC). Device interrogation revealed impaired atrial sensing, pacing thresholds, and impedance >2000 ohms (previously 480 ohms).The ventricular lead function was normal. Previous device interrogation 6 months back was normal. Chest X-ray showed a metallic stent in the right innominate vein with the struts in contact with the pacing leads ( Figure 1 ). Atrial lead replacement was not performed as per patient's request. The device was programmed to VVI(R) mode. Posteroanterior chest X-ray ( A ) showing the left prepectoral dual-chamber pacemaker generator, atrial and ventricular leads, and the right SVC stent. Arrow shows the area of stenosis and the SVC stent in position. The region of interest the stent ( B ) is enlarged with a schematic drawing and shown on the right side (B). The stent is in direct contact with the pacemaker leads (white arrow). Stenosis or occlusion of the SVC is a known complication of transvenous pacemakers. 1 Superior vena cava stenting has evolved to be a treatment modality for this complication, when symptomatic. 2 Though there was persistent concern that the metallic mesh of the stents may cause long-term damage to the pacemaker leads by direct compression, there is no published data of such lead damage. This case history shows the possibility of lead damage due to the metal stents. The damage to the atrial lead might have occurred immediately after deployment of the stent or later in time, most probably due to direct pressure on the lead. The functioning ventricular lead in this case may also get damaged in due course of time. This will be of a major clinical concern in pacemaker-dependent patients.