A small-molecule inhibitor of sarcomere contractility suppresses hypertrophic cardiomyopathy in mice

Powering down yields a healthier heart In hypertrophic cardiomyopathy (HCM), the heart muscle enlarges and becomes progressively less efficient at pumping blood. HCM can be caused by mutations in components of the sarcomere (the heart's contractile unit), most notably myosin. Hypercontractility is among the earliest heart disturbances seen in mice carrying these myosin mutations, implying that the mutations inflict their damage by increasing myosin's power production. Green et al. identified a small molecule that binds to myosin and inhibits its activity (see the Perspective by Warshaw). When orally administered to young mice, the molecule prevented the development of several hallmark features of HCM without adversely affecting skeletal muscle. Science , this issue p. 617 ; see also p. 556