The primary persistent Atrial fibrillation (AF) is the most common sustained arrhythmia in the general population; its prevalence increases with age and is generally associated with increased mortality. To decide the relationship between's left atrial capacity by dot following echocardiography and stroke chance in understanding with industrious atrial fibrillation. This examination included 100 patients with industrious AF convoluted with stir alluded to the Cardiology Department at Benha University Hospital for echocardiographic appraisal, who were contrasted and 100 patients with determined AF not entangled with stroke of coordinated age and sexual orientation. The collector administrator trademark (ROC) bend was utilized to test demonstrative estimation of different echocardiographic boundaries models in the connection between's left atrial capacity by dot following and stroke hazard in patients with tireless atrial fibrillation and indicated that the estimation of LA strain < 22.5 was appeared to have the best symptomatic precision with (affectability = 82%; explicitness = 60%) in foreseeing the stroke chance in atrial fibrillation understanding with AUC.871. It is reasoned that spot following investigations of the left chamber may offer important data on which patients would profit the most from delayed cardiovascular observing for distinguishing proof of PAF.