1. Cardiology Department, Royal Brompton and Harefield Hospital, Sydney Street, London SW3 6NP, UK
2. Nursing Faculty, Castilla-La Mancha University, Albacete, Spain
3. Cardiology Department, Congenital Heart Disease, “La Paz” Hospital, Madrid, Spain
4. Cardiology Department, “Gregorio Marañón” University Hospital, Madrid, Spain