Novel mechanism of premature battery failure due to lithium cluster formation in implantable cardioverter-defibrillators.

Background Battery failure is an uncommon complication of implantable cardioverter-defibrillators (ICDs), but unanticipated battery depletion can have life-threatening consequences. Objective The purpose of this study was to describe the prevalence of a novel mechanism of battery failure in St. Jude Medical Fortify and Unify ICDs. Methods Cases of premature Fortify battery failure from a single center are reported. A search (January 1, 2010 through November 30, 2013) for Fortify and Unify premature batter failure was conducted of the Food and Drug Administration's Manufacturer and User Facility Device Experience Database (MAUDE). These findings were supplemented with information provided by St. Jude Medical. Results Premature battery failure for 2 Fortify ICDs in our practice were attributed to the presence of lithium clusters near the cathode, causing a short circuit and high current drain. The prevalence of this mechanism of premature battery failure was 0.6% in our practice. A MAUDE search identified 39 cases of Fortify (30) and Unify (9) premature battery depletion confirmed by the manufacturer, representing a 0.03% prevalence. Four additional Fortify and 2 Unify cases were identified in MAUDE as suspected premature battery depletion, but in these cases the pulse generator was not returned to the manufacturer for evaluation. St. Jude Medical identified 10 cases of premature battery failure due to lithium clusters in Fortify devices (9) and Unify devices (1), representing a 0.004% prevalence. Conclusion The deposition of lithium clusters near the cathode is a novel mechanism of premature battery failure. The prevalence of this problem is unknown. Providers should be aware of this mechanism for patient management.