1. From the Department of Medicine, Division of Cardiology, Johns Hopkins Medical Institutions (M.C.P.H., H.S.S., E.S., G.G., S.P.S.), and the Department of Medicine, Good Samaritan Hospital (E.T.), Baltimore, Md; the Department of Medicine, Division of Cardiology, Uniformed Services University of the Health Sciences, Bethesda, Md (M.C.P.H.); Intracellular Diagnostics, Inc, Foster City, Calif (B.S.); and the Department of Cardiac Surgery, California Pacific Medical Center, San Francisco, Calif (J.D.H.).