1. From the Department of Medicine (J.E.S., M.I.B., T.H.M.), School of Human Movement Studies (J.E.S., J.S.C.), and Department of Cardiology (R.L., J.F., P.G.), University of Queensland, Princess Alexandra Hospital, Queensland, Australia; Department of Engineering (A.M.Q.), University of New South Wales, Sydney, Australia; and Clinical Pharmacology Unit (I.B.W.), University of Cambridge, Addenbrooke’s Hospital, Cambridge, United Kingdom.