The subcutaneous defibrillator.

Prevention of sudden cardiac death (SCD) remains an important clinical problem. Currently, therapeutic goals for SCD prevention include identification of high risk patients and aggressively treating comorbidities underlying. However, many patients remain at increased risk despite optimal medical management (eg, coronary artery disease and cardiomyopathy) whereas others have nonmodifiable risk for sudden death (eg, arrhythmogenic right ventricular dysplasia/cardiomyopathy, Brugada syndrome, long QT syndrome, and hypertrophic cardiomyopathy). In such patients, device therapy with an implantable defibrillator remains the most effective therapy for SCD prevention. However, implantable cardioverter defibrillators (ICDs), which are typically implanted with at least 1 lead placed within the heart, are associated with risks related to device implantation, as well as the presence of chronic endovascular leads. The durability of chronic leads is variable and can require either new leads to be placed or require lead extraction, which is associated with significant morbidity and mortality. The recently developed subcutaneous ICD (S-ICD) does not rely on any component to be placed within the heart or vasculature and therefore may mitigate the risks associated with endovascular leads. Therefore, it may be preferred for patients who are young, have inherited channelopathies, are immunocompromised, have indwelling catheters, or in whom venous access is obstructed or unfavorable due to congenital heart disease. Though long-term data regarding S-ICD performance are not yet available it may prove to be an effective therapeutic option for prevention of SCD.