Increasing clinician awareness, earlier diagnosis, and implantable cardioverter-defibrillators have allowed hypertrophic cardiomyopathy to transition from being a relatively common cause of sudden death in young people to a chronic disease affecting middle-aged and older people. Mechanistic understanding of hypertrophic cardiomyopathy has been informed by elegant gene discovery studies identifying pathogenic variants in genes encoding contractile proteins, which has led to the definition of disease of the sarcomere. However, until the development of mavacamten, this definition was not accompanied by disease-specific therapies.