Atrial fibrillation is a severe atrial arrhythmia, which on auscultation is characterized by a variable first heart sound and an absolutely irregular heart rate. The electrocardiogram shows the disappearance of P-wave, which is replaced by absolutely irregular f-wave. It is recommended that the patient go to the hospital in time for basic examinations. For example, blood routine, liver and kidney function, thyroid function tests, to exclude hyperthyroidism, while facilitating the use of amiodarone in the process of conversion. Secondly, chest X-ray, cardiac ultrasound, and esophageal ultrasound are all routine examinations that can assess whether the patient has atrial embolism and other conditions.