1. From the Hypertrophic Cardiomyopathy Center, Division of Cardiology, Tufts Medical Center, Boston, MA (M.S.M., C.H., J.E.U.); Referral Center for Myocardial Diseases, Azienda Ospedaliera Universitaria Careggi, Florence, Italy (I.O.); PERFUSE Core Laboratory and Data Coordinating Center, Harvard Medical School, Boston, MA (E.A., C.M.G., W.J.M.); Department of Medicine, Cardiovascular Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (E.A., C.M.G., W.J.M.); and...