1. From the Clinical Pharmacology Unit (C.M.M., Y., K.M.M.-P., S.S.H., I.B.W.), University of Cambridge, Addenbrooke’s Hospital, Cambridge, United Kingdom; Department of Cardiology (B.J.M., M.M., J.R.C.), University of Cardiff, University Hospital, Cardiff, United Kingdom; Department of Medicine (S.S.F.), University of California, Irvine, Calif.