Objective: Speckle tracking echocardiography is recently available method to assess left atrial (LA) deformation. The purpose of our study was to evaluate influence of LA structural and functional remodeling on antiarrhythmic effect of amiodarone and sotatol in patients (pts) with paroxysmal and persistent atrial fibrillation (AF). Design and method: The study included 60 patients [mean age 65 (60; 72) yrs, 45% men] with paroxysmal and persistent AF. AF duration was 28 (20; 59) months. Seven (12%) pts had previous stroke, 16 (27%) pts had history of prior MI, 14 (23%) pts had diabetes mellitus. The first group (n = 30) received 200 mg amiodarone plus 100 mg metoprolol daily, the second one (n = 30) received 160 mg sotalol daily. Echocardiography with Doppler technique and speckle tracking analysis was performed in the sinus rhythm period. LA enlargement was defined as LA volume index (LAVI) > 29 mL/m2. Global peak LA longitudinal strain (PALSr) < 14% was categorized as severe LA dysfunction. Results: Forty-six (77%) pts had increased LAVI, 34 (57%) pts had severe reduction of PALSr. Recurrence rate of AFib in pts with LA enlargement was higher than in pts with normal LAVI (1,69 ± 0,10 vs 0,85 ± 0,07 per 3 months, respectively, p = 0,03) as well as in pts with severe LA dysfunction as compared to pts with PALSr > 14% (1,35 ± 0,18 vs 0,725 ± 0,07 per 3 months, respectively, p = 0,04). Complete prevention of AFib was achieved in 26 (57%) pts with elevated LAVI and 9 (64%) pts with normal LAVI (p = 0,83), in 12 (35%) pts with severe LA dysfunction and 23 (89%) pts with moderate LA dysfunction (p = 0,001). Higher PALSr was significantly related with complete prevention of AFib (r = 0,35; p < 0,05). Conclusions: Complete antiarrhythmic effect of amiodarone and sotalol to prevent recurrent attacks in pts with paroxysmal and persistent AFib was correlated with global PALSr.