The level of systemic inflammation in the pre-ablation and immediate post-ablation period will be assessed on the basis of serum levels of inflammatory biomarkers (hsCRP, matrix metalloproteases, interleukin-6), while the level of cardiac fibrosis will be determined based on cardiac magnetic resonance imaging associated with complex post-processing techniques for mapping myocardial fibrosis at the level of left atrium and left ventricle. This evidence concerns the gene IL6 and Myocardial fibrosis.