Advances in Arrhythmia and Electrophysiology Minimizing Inappropriate or “Unnecessary” Implantable Cardioverter-Defibrillator Shocks Appropriate Programming

Life-saving shocks are the raisons d’être of implantable cardioverter-defibrillators (ICDs). Paradoxically, shocks also cause much of the morbidity associated with ICDs. Consistently, shocks reduce quality of life,1,2 and rarely, they may cause proarrhythmia.3,4 Additionally, shocks have been reported to be associated with excess mortality.5 Experts disagree about whether shocks are responsible for this excess mortality,6 but they do agree that ICDs should deliver the fewest shocks necessary to protect patients from ventricular tachycardia (VT) or ventricular fibrillation (VF). Minimizing ICD shocks requires a comprehensive approach, beginning with patient selection,7 general medical care (eg, preventing electrolyte abnormalities), and general cardiac care (preventing ischemia and treating heart failure). It includes the use of antiarrhythmic drugs and catheter ablation both to prevent VT or supraventricular tachycardia (SVT) and to control the ventricular rate in atrial fibrillation (AF) as well as the appropriate choice of hardware and device programming. This review focuses on ICD features and programming to minimize shocks.