Atrial septal defect (ASD) is a common congenital heart disease, and percutaneous interventional therapy is the main and effective treatment. Traditional percutaneous closure procedures are performed under fluoroscopic guidance and require contrast agents. A retrospective analysis of over 20,000 adult patients with congenital heart disease revealed that even low-dose radiation exposure was significantly associated with an increased long-term risk of malignancy. Moreover, the use of contrast agents carries the risk of allergic reactions and kidney injury. Radiation and contrast agents not only pose iatrogenic harm to patients but also limit the use of interventional techniques in special populations, such as pregnant women, patients with contrast agent allergies, or those with renal insufficiency.

To achieve radiation-free and contrast-free interventional closure procedures, researchers have developed ultrasound-guided percutaneous interventional techniques, yielding satisfactory treatment outcomes. In some cases, these techniques have even enabled cardiovascular procedures to be performed on an outpatient basis, significantly reducing hospitalization time and costs.

This project proposes a large-sample, multicenter, prospective randomized controlled study to determine whether ultrasound-guided percutaneous intervention for ASD with the assistance of specialized instruments is non-inferior to traditional fluoroscopy-guided procedures, while also offering shorter hospital stays and lower medical expenses.In addition, patients with radiation contraindications or who refuse radiation therapy, and who are willing to undergo ultrasound-guided percutaneous atrial septal defect (ASD) closure with the assistance of dedicated devices, will be enrolled in a separate observational cohort (observational cohort study).

RCT Eligibility Criteria

Inclusion Criteria:

• Age ≥ 2 years
• Diagnosed with secundum-type atrial septal defect (ASD) with a diameter ≥ 6 mm and ≤ 36 mm, accompanied by right heart volume overload
• The distance from the defect margin to the coronary sinus, inferior vena cava, superior vena cava, and pulmonary veins is ≥ 5 mm; the distance to the atrioventricular valve is ≥ 7 mm

Exclusion Criteria:

• Pregnant women
• Contrast agent allergy
• Renal insufficiency
• Associated cardiac malformations requiring surgical intervention
• Right-to-left shunt ASD
• Ostium primum ASD and sinus venosus ASD
• Any severe infection within one month before the procedure
• Intracardiac thrombus

Cohort Eligibility Criteria：

Inclusion Criteria:

• Age ≥ 2 years
• Diagnosed with secundum-type atrial septal defect (ASD) with a diameter ≥ 6 mm and ≤ 36 mm, accompanied by right heart volume overload
• The distance from the defect margin to the coronary sinus, inferior vena cava, superior vena cava, and pulmonary veins is ≥ 5 mm; the distance to the atrioventricular valve is ≥ 7 mm
• Contraindications to radiation exposure or refusal to undergo fluoroscopy-guided procedures

Exclusion Criteria:

• Associated cardiac malformations requiring surgical intervention
• Right-to-left shunt ASD
• Ostium primum ASD and sinus venosus ASD
• Any severe infection within one month before the procedure
• Intracardiac thrombus