A Better Method for Preventing Adverse Clinical Events Caused by Implantable Cardioverter-Defibrillator Lead Fractures?

摘要

In October 2007, the Medtronic Sprint Fidelis implantable cardioverter-defibrillator (ICD) lead was voluntarily withdrawn from the market by the manufacturer because of a higher-than-expected fracture rate. Most Sprint Fidelis fractures involve the pace-sense component of the lead, which may cause oversensing of electrical artifacts, undersensing of ventricular depolarizations, and/or loss of ventricular capture. Approximately 10% to 20% of Sprint Fidelis fractures involve the high-voltage conductor, which may compromise defibrillation. The most common clinical consequence of pace-sense conductor fracture is inappropriate shocks, which often occur in painful clusters and without warning. Inappropriate shocks may be proarrhythmic and lethal, and patients who experience them may suffer psychological sequelae. ICD lead failures are more likely to result in oversensing than pacemakers because the ICD pulse generators use high-sensitivity amplifiers to effectively detect ventricular fibrillation (VF). In this issue of Circulation, Swerdlowet al describe a new algorithm that may avoid or reduce inappropriate shocks and other serious adverse events in patients with failed Sprint Fidelis and possibly other high-voltage leads. If this algorithm proves to be safe and effective, it will be an important advance in ICD therapy.