Atrial fibrillation (AF) is an abnormal heart rhythm characterised by rapid and irregular beating. Most episodes have no symptoms. Occasionally there may be heart palpitations, fainting, shortness of breath, or chest pain.The disease increases the risk of heart failure, dementia, and stroke. The role of echocardiographic imaging among patients with atrial fibrillation (AF) can be divided into several categories: 1) Assessment of cardiac chamber sizes and function, the pericardium, and valvular function. This information may be helpful in determining the conditions associated with AF, and risk for recurrent AF following cardioversion. 2) Identification of patients at increased risk for thromboembolic complications of AF before cardioversion and in patients with chronic AF.