The aim – to create model for evaluation of left atrial appendage dysfunction in patients with atrial fibrillation (AF). We evaluated 246 patients with AF by transesophageal and transthoracic echocardiography. Low left atrial appendage velocity (LAAV) ≤ 25 cm/s was found in 40.65 % of cases. Patients with LAAV ≤ 25 cm/s had significant association with presence of severe spontaneous echo contrast and LAA thrombi (Р<0.0001). TDI was used to acquire Em and 2D to measure left atrial volume index. There was significant correlation between these sole parameters and LAAV. Linear regression model was tested prospectively in 184 patients with AF episode; its specificity 87.4 %, sensitivity 61.6 %, positive 76.3 % and negative 77.6 % predictive values were proved. The elaborated linear regression model may be used to estimate low LAAV with reasonable accuracy in patients with AF episode.