Search results and studies characteristics
2312 articles were retrieved by the electronic search and 3 additional articles were identified by hand-search. The flow of study selection is depicted in Figure 1. 17 articles were considered to be eligible and were included in the final analysis[13-29]. We analyzed 1704 patients (68.6% men) with a pooled mean (SD) age of 59.9(10.6) years. Among them 65.9% had PAF, while the main comorbidities were hypertension (51.6%) and diabetes mellitus (11%). The baseline pre-ablation weighted mean (SD) maximum LA volume index (LAVi) and left ventricular ejection fraction were 38.38 (16.27) and 61.5% (9%), respectively. For quantification of LA-PLSsys most studies used the EchoPac PC, GE Vingmed, Horton, Norway software, with the vast majority of the researches measuring LA-PLSsys in at least 6 segments. Two studies included a mixed population of patients who underwent first and second PVI procedure[20, 22], while in one study the majority of patients were treated with electrical cardioversion prior to CA procedure (LA-PLSsys was measured before cardioversion)[29]. AF recurrence occurred in 32.7% of the patients analyzed. Studies characteristics are summarized in Table 1.