1 Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, CIBERCV, Manuel de Falla, 2, 28222 Madrid, Spain.
2 Centro Nacional de Investigaciones Cardiovasculares (CNIC), C/ de Melchor Fernández Almagro 3, 28029 Madrid, Spain.