1. Department of Echocardiography and Paediatric Cardiology, Royal Brompton and Harefield, National Health Service (NHS) Foundation Trust, London, United Kingdom
2. Department of Cardiology and Aortic Centre, Royal Brompton & Harefield National Health Service Foundation Trust, London, United Kingdom
3. National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, United Kingdom
4. Department of Cardiology, Nicosia General Hospital, Strovolos, Cyprus
5. Department of Echocardiography and Congenital Heart Disease, Royal Brompton & Harefield National Health Service Foundation Trust, London, United Kingdom