^*major risk factor for SCD in HCM: prior cardiac arrest, spontaneous sustained or nonsustained VT, family history of SCD, syncope, LV thickness ≥30 mm and an abnormal blood pressure response to exercise, ^†risk factor for SCD in ARVC: presence of a previous cardiac arrest, syncope due to VT, evidence of extensive RV disease, LV involvement, or presentation with polymorphic VT and RV apical aneurysm, which is associated with a genetic locus on chromosome 1q42–43. ICM: ischemic cardiomyopathy, NICM: nonischemic cardiomyopathy, LOE: level of evidence, LVOT: left ventricular outflow tract, LVEF: left ventricular ejection fraction, SCD: sudden cardiac death, RV: right ventricle, LV: left ventricular, ARVC: arrhythmogenic right ventricular cardiomyopathy, ICD: implantable cardioverter-defibrillator, VT: ventricular tachy-cardia, MI: myocardial infarction, NYHA: New York Heart Association. Adapted from Epstein et al. J Am Coll Cardiol 2013;61:e6-e75 [8]