1. Cardiology Department, Northwick Park Hospital, London North West University Healthcare NHS Trust, Watford Road, Harrow, London, HA1 3UJ, UK
2. Cardiac Electrophysiology Group, Cardiology Department, Royal Brompton Hospital, Royal Brompton and Harefield NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK
3. Structural Heart Disease Group, Cardiology Department, Royal Brompton Hospital, Royal Brompton and Harefield NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK