Lead noise with an active-fixation defibrillation lead

Inappropriate detection and therapy is the most common adverse effect of implantable cardioverter defibrillator therapy. One mechanism is lead artifact, which usually presents late and is due to stress and fatigue of the lead components. Our experience with a defibrillator lead (Endotak Endurance EZ leads, Models 0154/0155/0156) and its method of active fixation is described. Of 20 implants with this lead, four patients were found to have noise that resulted in inappropriate detections in three. No patient received therapy as a consequence of these detections. The artifact appeared soon after implant and resolved in three of four cases by 4 weeks. None of the 16 remaining patients developed noise after this time. This is a unique lead problem that resolves with time, but it may result in inappropriate therapies and difficult management decisions in high risk patients with ventricular arrhythmias.