GUIDELINE TITLE 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death RELEASE DATE September 25, 2018 PRIOR VERSIONS 2008 ACC/AHA/HRS Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities (specifically sections on indications for implantable cardioverter-defibrillators [ICDs]) DEVELOPER American College of Cardiology (ACC), American Heart Association (AHA), and Heart Rhythm Society (HRS) FUNDING SOURCE ACC and AHA TARGET POPULATION Adult patients with ventricular arrhythmias or at risk of sudden cardiac death MAJOR RECOMMENDATIONS In patients with heart failure with reduced ejection fraction (< 40%), guideline-directed medical therapy (GDMT) is recommended to reduce sudden cardiac death and all-cause mortality; GDMT includes beta-blockers; mineralocorticoid receptor antagonists; and angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, orangiotensin receptor-neprilysin inhibitors (class I, level A recommendation). In patients with left ventricular ejection fraction (LVEF) of 35% or less due to ischemic heart disease at least 40 days after myocardial infarction, at least 90 days after revascularization, and with New York Heart Association (NYHA) class II or III heart failure despite GDMT, an ICD is recommended if expected survival is greater than 1 year (class I, level A recommendation). In patients with LVEF of 30% or less due to ischemic heart disease at least 40 days after myocardial infarction, at least 90 days after revascularization, and with NYHA class I heart failure symptoms despite GDMT, an ICD is recommended if expected survival is greater than 1 year (class I, level A recommendation). In patients with nonischemic cardiomyopathy, NYHA class II to III symptoms, and LVEF of 35% or less despite GDMT, an ICD is recommended if expected survival is greater than 1 year (class I, level A recommendation).