1. Adult Congenital Heart Centre and National Centre for Pulmonary Hypertension, Royal Brompton and Harefield Hospitals, Guys & St Thomas’s NHS Trust , Sydney Street, London SW3 6NP , UK
2. National Heart & Lung Institute, Imperial College , South Kensington Campus, London SW7 2AZ , UK
3. Medical Faculty University of Rijeka , Ul. Braće Branchetta 20/1, 51000 Rijeka , Croatia