This review in Circulation on risk stratification and prevention of sudden death in hypertrophic cardiomyopathy covers the following topics:

• Epidemiology of sudden death

• Arrhythmogenic substrate

• Sudden death prevention: historical context

• Implantable cardioverter-defibrillator (ICD) experience in hypertrophic cardiomyopathy

• Unpredictable substrate

• Selection of patients for ICDs

• Translating risk factors to clinical practice

• Other considerations affecting ICDs

• Strategies for sudden death prevention: Targeting patients for ICD therapy