What is the recommended management for a patient with an Atrial Septal Defect (ASD)?

Management of Atrial Septal Defect (ASD)

Close all hemodynamically significant ASDs (defined by right atrial and right ventricular enlargement) regardless of symptoms, using percutaneous device closure for secundum defects and surgical closure for all other subtypes. 1, 2

Diagnostic Confirmation

Before proceeding with closure, confirm the diagnosis with imaging that demonstrates:

• Shunting across the defect with evidence of RV volume overload 3
• ASD subtype classification (secundum, primum, sinus venosus, or coronary sinus defect) 3
• Associated anomalies, particularly partial anomalous pulmonary venous connection 3

Patients with unexplained RV volume overload require referral to an adult congenital heart disease (ACHD) center to rule out obscure defects. 3

Avoid diagnostic cardiac catheterization in younger patients with uncomplicated ASD when noninvasive imaging is adequate. 3 However, catheterization is reasonable to exclude coronary artery disease in older patients or those with risk factors. 3

Treatment Algorithm by ASD Subtype

Secundum ASD (>90% of cases)

Percutaneous device closure is first-line treatment when right atrial and RV enlargement are present, with or without symptoms (Class I indication). 1, 2

Surgical closure is indicated when:

• Concomitant tricuspid valve repair/replacement is needed 3, 2
• Defect anatomy precludes percutaneous device use (typically defects >38 mm or those with deficient rims) 3, 4

Non-Secundum ASDs

All sinus venosus, primum, and coronary sinus defects require surgical closure—these are not amenable to percutaneous devices. 3, 1, 2 Surgery must be performed by surgeons with specific training and expertise in congenital heart disease. 3

Specific Indications for Closure

Class I (Must Close):

• Right atrial and RV enlargement with or without symptoms 3, 1, 2
• Qp:Qs ratio ≥1.5:1 with RV enlargement 2

Class IIa (Should Close):

• Paradoxical embolism 3, 2
• Documented orthodeoxia-platypnea syndrome 3

Class IIb (May Consider Closing):

• Net left-to-right shunt with pulmonary artery pressure <2/3 systemic levels AND pulmonary vascular resistance (PVR) <2/3 systemic vascular resistance 3

Critical Contraindications (Class III - Do Not Close)

Absolute contraindications:

• Severe irreversible pulmonary arterial hypertension (PAH) with no evidence of left-to-right shunt 2
• PA systolic pressure >2/3 systemic 2
• PVR >2/3 systemic vascular resistance 3, 2

Closure with established severe pulmonary vascular disease is fatal. 2 Patients with severe PAH require evaluation by providers with expertise in pulmonary hypertensive syndromes before any consideration of closure. 1

Small ASDs (<5 mm)

Do not close small defects without RV volume overload unless associated with paradoxical embolism. 1 These patients require:

• Assessment for arrhythmias and paradoxical embolic events 3
• Repeat echocardiography every 2-3 years to monitor RV size, function, and pulmonary pressure 3

Critical pitfall: Do not assume small shunts remain benign in older adults. Acquired conditions (hypertension, coronary artery disease, valvular disease) reduce LV compliance and increase left-to-right shunting over time, making previously insignificant ASDs hemodynamically relevant. 3, 2

Arrhythmia Management

Treat atrial arrhythmias aggressively to restore and maintain sinus rhythm. 3, 2 If atrial fibrillation occurs, initiate both antiarrhythmic therapy and anticoagulation. 3

Pre-closure ablation is reasonable for patients with supraventricular tachycardia undergoing ASD closure. 2 This addresses the substrate before anatomic repair.

Post-Closure Monitoring

Perform echocardiography to assess:

• Device position and stability 1
• Residual shunting 1
• Pericardial effusion 1
• RV function 1

Monitor for postpericardiotomy syndrome, which presents with fever, fatigue, vomiting, chest pain, or abdominal pain and may indicate tamponade. 1 Early mortality is approximately 1% in the absence of PAH or major comorbidities. 1

Expected Outcomes and Timing Considerations

Closure improves:

• NYHA functional class 3, 1
• RV systolic pressure, volumes, and dimensions 3, 1
• Exercise tolerance, particularly in patients >40 years 1
• Adjusted mortality rate (weak protective effect) 3, 1

Critical timing consideration: Surgery performed after age 25 years results in reduced survival compared to age-matched controls. 1 Nearly 25% of patients with unoperated ASDs die before age 27, and 90% by age 60. 1 Do not delay closure based on absence of symptoms—symptoms lag behind objective cardiopulmonary dysfunction and cannot guide therapy. 1