1. From the Departments of Cardiology (V.J.H.M.v.D., K.G.E.J.N., H.v.W., B.C.d.P., P.A.F.M.D., F.H.M.W.) and Pathology (A.V.), University Medical Center, Utrecht, The Netherlands; and Department of Rhythmology, Alfried Krupp Hospital, Essen, Germany (K.G.E.J.N.).