“…Different methods have been introduced to identify such remodelled atrial substrates to guide persAF ablation -such as fractionated atrial electrograms (AEGs) and functional re-entrieswith promising initial results [2,3]. More recent works, however, could not reproduce such results [4,5], possibly due to the existence of multiple mechanisms participating -either simultaneously or intermittently -in its perpetuation [2,3,6], methodological heterogeneities [7], and poor understanding of the underlying AF dynamics [4,6,8,9]. Therefore, biological markers that better explain AF behaviour to guide ablation are still in debate.…”