BACKGROUND: Paroxysmal atrial fibrillation (AF) (PaAF) has ariable proression after sinus conversion. We investigated predictors of recurrence in patients with PaAF. METHODS: The study population included 228 PaAF patients (131 men, age 64짹14 years) who underwent transthoracic echocardiography immediately after sinus conversion at initial AF diagnosis. We followed study patients for AF recurrence. RESULTS: Among 228 patients, AF recurrence was demonstrated in 45 patients (20%, age 68짹13 years) after sinus conversion. Recurrence group had larger left atrial (LA) volume index (LAVI, 32짹12 vs. 25짹10 ml/m2, P<0.001) and E/e' (14짹7 vs. 12짹5, P=0.012), while early diastolic mitral annular velocity (e���, 5짹2 vs. 6짹3 cm/s, P=0.021) and late diastolic mitral annular velocity (A���, 7짹3 vs. 9짹2 cm/s, P<0.001) were significantly lower. In multivariate Cox regression analysis detecting independent predictors of PaAF recurrence, lower A��� (HR 0.620, 95% CI 0.458-0.839, P=0.002) were independently significant predictors of AF recurrence. CONCLUSIONS: Late diastolic mitral annular velocity (A���) which indicates LA systolic function after sinus conversion was the independent predictor of PaAF recurrence, whereas LA volume was not. LA function may be more important than LA volume in predicting recurrence particularly in patients with PaAF.