1 Department of cardiovascular imaging, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, United Kingdom, WC1N 3JH.
2 Department of Adult Congenital Heart Disease, Liverpool Heart and Chest NHS Trust, Liverpool, United Kingdom.
3 Cardiology Department, Royal Berkshire Hospital, Reading, UK.
4 Adult Congenital Heart Centre and Centre for Pulmonary Hypertension, Royal Brompton Hospital, Royal Brompton & Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London, UK.
5 National Heart and Lung Institute, Imperial College London, London, United Kingdom.
6 Department of Cardiology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, United Kingdom.