Atrial septal defect (ASD) is a common congenital cardiac malformation that is caused by an abnormality of the original atrial septum during embryonic development, leaving a gap between the left and right atria. ASDs can occur alone or in conjunction with other types of cardiovascular malformations and are more common in females, with a male to female ratio of approximately 1:3. Due to the presence of shunts at the atrial level, they can cause corresponding hemodynamic abnormalities.1 The overall rate of natural closure of atrial septal secondary foramen ovale defects is 87%. Atrial septal defects with defects <3 mm diagnosed before 3 months of age can be 100% spontaneously closed within 1.5 years of age; atrial septal defects with defects 3-8 mm can be spontaneously closed in more than 80% of cases within 1.5 years of age; those with defects above 8 mm are rarely spontaneously closed. Most children with atrial septal defects are generally asymptomatic and do not affect their activities; heart failure can occur in infants, but it is very rare. If left untreated, congestive heart failure and pulmonary hypertension will occur in adults around the age of 20 or 30. 4. Atrial arrhythmias (atrial flutter or atrial fibrillation) can develop in adulthood with or without surgical treatment. 5, Simple atrial septal defect will not develop infective endocarditis, so if there are no other combined malformations, prophylactic treatment is not necessary. 6, cerebrovascular accidents, cerebrovascular embolism caused by paradoxical thrombosis due to atrial septal defect is a relatively rare complication.