Atrial septal defect is a common congenital heart disease, accounting for about 1/1500 of newborns, and is most commonly found in infants and children. The impact of atrial septal defects on hemodynamics mainly depends on the amount of shunting. Some studies confirm that atrial septal defects smaller than six millimeters can close on their own without external intervention. Therefore, when an atrial septal defect is discovered, it is necessary to regularly recheck the cardiac echocardiography to determine the size of the defect. If the atrial septal defect decreases in size as the patient ages, there is a possibility of self-healing. If the area of the patient's atrial septal defect does not change or gradually increases, regular echocardiography rechecks are needed, and cardiac catheterization may be performed if necessary.