Study selection
All articles that were obtained after the initial search, were screened by two independent reviewers (I.A. and M.K.) based on title and abstract. Subsequently, potentially eligible studies were further reviewed for inclusion in the final analysis based on the full text. Any disagreements were resolved after consensus with an expert (G.G.). Eligibility criteria for inclusion were: a) prospective or retrospective studies including patients with paroxysmal or/and persistent AF, b) endocardial pulmonary venous isolation (PVI) with radiofrequency catheter ablation (RFCA) or cryoballoon ablation, c) pre-procedural quantification of LA-PLSsys, averaged in at least two segments, using 2DSTE d) a follow-up of at least 6 months for post-ablation AF recurrence.