Background: Concomitant atrial fibrillation (AF) in non-ST segment elevation acute coronary syndrome (NSTE-ACS) patients complicates the decision-making process regarding short- and long-term antithrombotic strategies. Patient profiles and usage rates of different antithrombotic combinations in this patient subgroup in Romania are poorly described. Study aim: To evaluate the relationship between LA dimensions and AF recurrences (AFR) using echocardiography. Methods: We enrolled 40 patients (56 ± 10 years; 73% males) who underwent a first RFCA for paroxysmal AF. Bi- (2DE) and three-dimensional (3DE) echocardiography was performed prior to RFCA and at 12-months follow-up. Rhythm control was monitored for up to two years after the intervention by periodic ECG Holter monitoring. Results: Atrial fibrillation recurrences were recorded in 21 patients (52%) in the first year after RCFA. The only predictor of outcome from pre-ablation LA parameters was 3DE minimum LAVi (p = 0.042), that explained 21.4% of AF recurrences in the first year, with a cut-off value of 21.29 mL/m². The mean 3DE min LAVi was 24.29 ± 8.01 mL/ m² and patients without AFR in the first year had a lower LAVi than those with AFR (20.92 ± 6.19 mL/m² vs. 27.25 ± 8.43 mL/m², p=0.028). One year after RFCA, a decrease in medio-lateral, superior-inferior diameters and volumes were recorded in AF free patients. Eleven patients (27%) had AF recurrences after the first year and LAV 12-months after RFCA were found to be predictors of long-term outcome, with minimum LAVi as the strongest predictor of recurrences (p=0.014), explaining 36% of episodes, with a cut-off over 22.49 mL/m². Conclusion:Radiofrequency ablation controls LA remodeling in patients with clinical success in terms of AF freedom. Left atrium 3DE volumetry is accurate in predicting RFCA outcome.