Limitations:
The most important limitation of our study is its single center and crosssectional design and relatively small number of patients. Further prospective studies with larger number of patients are needed on this issue. Although speckle tracking echocardiography is considered angle independent, echocardiographic image quality should be adequate to perform an optimal analysis, as there is presently no software dedicated for the evaluation of atrial. The another limitation of our study, some asymptomatic patients may not have presented with AF during the 24-hour period of Holter monitoring, our study may underrepresent the prevalence of asymptomatic AF patients. Since the interval between initial assessment follow up visits was relatively prolonged, this may lead to underestimate atrial fibrillation that may develop.