Affiliations:
  1. Royal Brompton & Harefield Hospital National Health Service Foundation Trust, Hill End Road, Harefield, Uxbridge, UB9 6JH, United Kingdom
  2. Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.
  3. Hull Family Cardiac Fibrillation Management Laboratory, Division of Cardiology, University Health Network, Toronto General Hospital, Toronto, Ontario, Canada