1. From the Danish National Research Foundation Centre for Cardiac Arrhythmia (I.E.C., M.S.O., S.H., J.H.S.), Laboratory of Molecular Cardiology, Department of Cardiology, Rigshospitalet, Copenhagen University Hospital (I.E.C., M.S.O., S.H., J.H.S.), Departments of Biostatistics (E.B.-J.) and Surgery and Medicine (S.H., J.H.S.), Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Departments of Clinical Genetics, Clinical Biochemistry and Pharmacology, Odense University Hospital,...