1. Bristol Medical School, University of Bristol, Bristol Royal Infirmary, Upper Maudlin St, Bristol, BS2 8HW, UK
2. Bristol Heart Institute, Bristol Royal Infirmary, Upper Maudlin St, Bristol, BS2 8HW, UK
3. Pediatric Cardiology Unit, Hospital Virgen del Rocio and Institute of Biomedicine of Seville (IBIS), Seville, E-41013, Spain
4. School of Biomedical Engineering and Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, SE1 7EH, UK
5. Department of Clinical Radiology, Bristol Royal Infirmary, Upper Maudlin St, Bristol, BS2 8HW, UK
6. National Heart and Lung Institute, Guy Scadding Building, Imperial College London, London, SW3 6LY, UK