Implantable cardioverter defibrillators: state of the art Jordan C Ray, Harrison M Goodall, Thomas E Pascual, Fred M Kusumoto Electrophysiology and Pacing Service, Division of Cardiovascular Disease, Department of Medicine, Mayo Clinic, Jacksonville, FL, USA Abstract: It has been estimated that 180,000–450,000 people die suddenly in the US every year. Currently, the most effective method for reducing the risk of sudden death in those patients at highest risk is implantation of an internal cardioverter defibrillator (ICD). The evidence base for the benefit of the ICD has matured over the last two decades, and large studies have consistently shown reduced mortality or sudden cardiac death (SCD) in selected patient populations. Since its initial application in the early 1980s in patients who had already suffered an episode of SCD (secondary prevention), ICD use has expanded dramatically and now includes patients who are at high risk for a first event of SCD (primary prevention). More recent studies have focused on new technology, optimal programming, and other gaps in our understanding of the use of ICDs. Keywords: sudden cardiac death, primary prevention, secondary prevention, myocardial infarction, ventricular fibrillation, ventricular tachycardia, LVEF, subcutaneous implantable cardioverter-defibrillator