1. From the Clinical Pharmacology Unit (Y., C.M.M., K.M.O., P.H., A.A., S.W., K.M.-P., M.J.A., I.B.W.), University of Cambridge, Addenbrooke’s Hospital, Cambridge; the Department of Cardiology (B.M., J.R.C.), University of Wales College of Medicine, Cardiff; and Trinity College (J.B.), Cambridge, UK.