trial fibrillation (AF) is the most common cardiac arrhythmia worldwide, and its prevalence continues to rise. AF is associated with serious complications, including embolic strokes, heart failure, and mortality. Characterized by rapid, irregular, and weakened contractions of the atria, AF is considered one of the "visible" electrophysiological manifestations of a broader condition known as atrial cardiomyopathy (ACM). Disruption of normal blood flow in the atrium, particularly in the context of an endocardium predisposed to thrombosis, predisposes to thrombus formation. Once dislodged from the atrial cavity and migrating to the cerebral arteries, these thrombi can cause a cardioembolic stroke. The main risk factors for ACI/AF are metabolic syndrome and aging. CMA is a condition that is difficult to diagnose because it is not clearly defined, except through histological analysis. Guided by the results of our experimental approaches, we aim to address this challenge by approaching CMA through one of its complications: persistent atrial fibrillation. Indeed, CMA can be assessed using electroanatomical mapping during atrial fibrillation ablation (AFA) procedures. During radiofrequency ablation of AF, electroanatomical mapping of the left atrium is performed to measure left atrial voltage, which serves as an indirect marker of the presence of atrial fibrosis, strongly associated with CMA. Other parameters relevant to the identification of CMA can be assessed during this procedure, such as conduction velocities and specific electrographic characteristics.

We plan to include 150 patients undergoing ablation for persistent atrial fibrillation at the Dijon Bourgogne University Hospital and to correlate circulating levels of BDNF (brain-derived neurotrophic factor) with electroanatomical mapping data of the left atrium. The electrical remodeling of the left atrium, including low-voltage areas and conduction velocity, as well as left atrial morphology assessed by pre-procedural cardiac computed tomography using the ADAS3 Galgo LA Module software, will be correlated with BDNF levels. Blood samples for BDNF assessment will be collected before or at the start of the ablation procedure, prior to any catheter insertion into the vessels.

While investigating the association between BDNF levels and CMA characteristics during AF ablation, thereby confirming the pathophysiological relationship with atrial remodeling, our objective is also to evaluate the prognostic role of BDNF levels in clinical and rhythm outcomes following AF ablation. Thus, we will compare changes in BDNF levels after AF ablation at one-year follow-up, correlating them with the evolution of CMA-based on left atrial parameters assessed by echocardiography or cardiac computed tomography-autonomic nervous system balance and heart rhythm obtained via Holter monitoring, as well as clinical outcomes.

Inclusion Criteria:

• Participants who have provided written consent
• Patients aged 18 years or older.
• Patients scheduled to undergo their first ablation procedure for persistent atrial fibrillation at the Dijon Bourgogne University Hospital

Exclusion Criteria:

• A person who is not enrolled in or eligible for a social security program
• A person subject to a legal protective measure (guardianship, conservatorship)
• Person subject to a judicial safeguard measure
• Pregnant or breastfeeding woman
• Adult who is legally incapacitated or unable to give consent
• Ablation of paroxysmal AF with or without electroanatomical mapping

Patients scheduled to undergo their first ablation procedure for persistent atrial fibrillation at the Dijon Bourgogne University Hospital.