An atrial septal defect of 13 mm is a moderate defect. Generally, a defect of 5 mm or less is a micro defect, a small defect of 10 mm or less, and a moderate defect of 10-20 mm. Once an atrial septal defect of 13mm occurs, two types of treatment can be given: the first one, minimally invasive interventional blocking treatment and open-chest direct vision repair treatment, both of which can cure the atrial septal defect, but the choice of treatment should be based on cardiac ultrasound. The next step of treatment can be determined by the ultrasound examination of the heart, which can determine the location and type of atrial septal defect. In the second one, cardiac diuretic and myocardial nourishing drugs are needed, which is the only way to make the patient recover faster.