1 Department of Cardiology, Cardiovascular Clinical Institute, UFA (Unitat de Fibril.laciò Auricular de l'Hospital Clìnic), Hospital Clìnic, Universitat de Barcelona, C/Villarroel 170, 08036 Barcelona, Spain.
2 Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, Spain.
3 Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.