Implantable cardioverter and defibrillator therapy

Internal cardioverter defibrillator (ICD) therapy is extremely effective in terminating ventricular tachycardia or ventricular fibrillation (VT/VF) and reducing total mortality in select populations. Common indications for ICDs include survival of prior cardiac arrest, unexplained syncope with inducible VT/VF on electrophysiology study, ischemic cardiomyopathy with EF ≤30 % in patients who are more than 40 days post-myocardial infarction, and cardiomyopathy (ischemic or nonischemic) with EF ≤35 % and New York Heart Association (NYHA) Class II-III heart failure symptoms. ICDs may also be indicated in certain individuals from special populations who suffer from inherited conditions which predispose to sudden cardiac death such as hypertrophic cardiomyopathy, long QT syndrome, Brugada syndrome, arrhythmogenic right ventricular dysplasia, catecholaminergic polymorphic ventricular tachycardia, and cardiac sarcoidosis.