Validation of the Efficacy of the Tool GIMIAS® for the Assessment of Left Atrial Fibrosis in a Group of Healthy Volunteers (RESTORE-HV)

Inclusion Criteria: * Healthy volunteers capable of being subjected to the prespecified tests of the study. * Healthy volunteers that sign the informed consent after being informed. Exclusion Criteria: * Healthy volunteers with: * A medical history of atrial fibrillation, hypertension or diabetes mellitus. * A medical history of heart disease, structural, ischemic or arrhythmic. * A medical history of chronic obstructive pulmonary disease/obstructive sleep apnoea/hypopnoea syndrome * Sport habits: intense sport activities during three or more hours in a week * Any assumption that contraindicates the magnetic resonance and/or the use of gadolinium or other contrast mediums, including a medical history of previous allergic or not allergic reactions with the use of gadolinium or other contrast mediums, bronchial asthma or allergic diseases. * Pregnancy or breast feeding.