Atrial septal defect is the most common congenital heart disease in adults, accounting for 20%-30% of adult congenital heart diseases, with a higher incidence in females than males, with a male to female ratio of about 1:1.5-3. There is also a familial tendency. Apart from larger defects, children with atrial septal defects generally show no symptoms. As they age, symptoms gradually appear, with exertional dyspnea being the main symptom, followed by supraventricular arrhythmias, especially atrial flutter and fibrillation, which exacerbate the symptoms. Some patients may develop right heart failure due to excessive right ventricular volume load. In the late stages, about 15% of patients develop severe pulmonary hypertension, resulting in a right-to-left shunt and cyanosis.