INCIDENCE, PRESENTATION, DIAGNOSIS, AND MANAGEMENT OF MALFUNCTIONING IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR RATE-SENSING LEADS

Recognition of tachyarrhythmia by an implantable cardioverter-defibril lator (ICD) requires an intact rate-sensing lead. We retrospectively e xamined 266 consecutive patients requiring an ICD to characterize the incidence, clinical presentation, diagnosis, and management of a defec tive rate-sensing lead. To identify clinical parameters that may contr ibute to lead complications, we also assessed the effects of age, gend er, type of rate-sensing lead, manufacturer of the lead, and surgeon. Over a follow-up period of 30 +/- 22 months (mean +/- standard deviati on), a defective lead was found in 9 (3.4%) patients, in 9 (1.7%) of 5 14 leads over a period of 2 to 39 (mean 17 +/- 15) months after implan tation. Except for 1 patient, in whom a lead fracture was incidently f ound during ICD generator replacement, these patients had multiple ina ppropriate shocks of recent onset. Clinical parameters were not helpfu l in identifying patients at risk for lead complication. An abnormal b eeping signal obtained while the patients performed various maneuvers was helpful in confirming a defect. All of the defective leads were ep icardial. These cases were managed by placement of a transvenous endoc ardial lead.