1. From the Department of Cardiology, Amsterdam University Medical Center, Amsterdam (R.E.K., L.V.A.B.), and the Department of Cardiology, St Antonius Ziekenhuis, Nieuwegein (L.V.A.B.) — both in the Netherlands; Emory University Section of Cardiac Electrophysiology, Atlanta (M.S.L., F.M.M.); University Hospital Southampton, Southampton (P.R.R.), the Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool (D.J.W.), and Leeds Teaching Hospitals NHS Trust, Leeds (C.P.), and Manchester...