Inclusion Criteria:  Adult patient, male or female, eligible for an AF ablation procedure according to the recommendations (European Society of Cardiology 2020 and American Society of Cardiology 2014), either for symptomatic paroxysmal AF refractory to anti-arrhythmic treatments (or in first intention according to patient preference), or for symptomatic persistent AF. Able to give their non-opposition to participate in the research. Affiliation to a social security regime.  Exclusion Criteria:  Any pro-fibrotic phenomenon that may interfere with the interpretation of the results, i.e. severe valvular heart disease, amyloid heart disease, dilated cardiomyopathy of non-rhythmic origin, hypertrophic cardiomyopathy, severe ischaemic heart disease (late revascularisation, LV dysfunction, disturbed kinetics), COPD > stage 2, pulmonary fibrosis, renal failure > stage 3A, hepatic cirrhosis, hepatocellular failure, recent invasive surgery < 3 months Life expectancy less than 1 year Pregnant or breastfeeding women Patients of legal age under protective supervision (guardianship, trusteeship) Refusal to participate