1 Adult Congenital Heart Centre and National Centre for Pulmonary Hypertension, Royal Brompton & Harefield NHS Trust, London, UK.
2 Adult Congenital Heart Centre and National Centre for Pulmonary Hypertension, Royal Brompton & Harefield NHS Trust, London, UK; National Heart and Lung Institute, Imperial College, London, UK; Department of Medical Rehabilitation, Medical Faculty, University of Rijeka, Croatia. Electronic address: [email protected].