1. Cardiology Clinical Academic Group, St George’s University Hospitals NHS Foundation Trust, London, United Kingdom (B.E., C.S., E.R.B.).
2. Institute of Molecular and Clinical Sciences, St George’s University of London, United Kingdom (B.E., C.S., E.R.B.).
3. Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver (C.C.C., A.D.K.).
4. Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada (F.A., J.D.R.).
5. Department of Cardiology, Rigshospitalet, Copenhagen, Denmark (B.G.W., J.T.-H.).
6. Royal Victoria Hospital, Belfast, United Kingdom (P.B., A.M.).
7. Imperial College Healthcare NHS Trust, London, United Kingdom (K.L., A.V.).
8. Section of Forensic Genetics, Department of Forensic Medicine, Copenhagen University, Denmark (J.T.-H.).