1. Department of Adult Congenital Cardiology, Queen Elizabeth Hospital Birmingham , Birmingham , UK
2. Adult Congenital Heart Centre and National Centre for Pulmonary Hypertension, Royal Brompton Hospital, Guy's and St Thomas’ Hospital NHS Foundation Trust , Sydney Street, Chelsea, London SW3 6NP, UK
3. National Heart and Lung Institute, Imperial College London , Guy Scadding Building, Dovehouse Street, London SW3 6LY, UK