What is the management approach for an adult with an atrial septal aneurysm?

Management of Atrial Septal Aneurysm in Adults

An isolated atrial septal aneurysm without an associated atrial septal defect or history of embolic events requires careful echocardiographic evaluation but typically does not need intervention—only clinical surveillance for potential thromboembolic complications. 1

Initial Diagnostic Approach

Perform comprehensive echocardiographic assessment to determine if the aneurysm is truly isolated or associated with other pathology:

• Use transesophageal echocardiography (TEE) rather than transthoracic echo alone, as TEE detects interatrial shunting in 83% of cases versus only 41% with transthoracic imaging, and can identify multiple fenestrations and thrombus within the aneurysm that transthoracic echo misses 2

• Specifically evaluate for:

  • Associated atrial septal defect (present in majority of cases with aneurysm) 1
  • Right atrial and right ventricular enlargement indicating hemodynamically significant shunting 1
  • Interatrial shunting using contrast imaging combined with color flow Doppler 2
  • Thickening of the aneurysmal membrane ≥5 mm (associated with 75% of embolic events versus 27% without events) 2
  • Thrombus within the aneurysm 2
  • Multifenestrated atrial septum 1

Management Algorithm Based on Findings

If Isolated Aneurysm WITHOUT Associated ASD:

Conservative management with surveillance is appropriate 3, 4:

• No intervention required if the patient has no history of embolic events and no thrombus is visualized 4
• Clinical follow-up to monitor for development of symptoms or complications 3
• No routine anticoagulation unless there is documented paradoxical embolism or other indication 4

If Aneurysm WITH Associated ASD:

The presence of an ASD changes management entirely—follow standard ASD closure indications 1, 5:

• Closure is indicated (Class I recommendation) if there is right atrial and right ventricular enlargement with or without symptoms 1
• Closure is reasonable (Class IIa) for paradoxical embolism or documented orthodeoxia-platypnea 1
• Small ASDs (<5 mm) without RV volume overload do not require closure unless associated with paradoxical embolism 1, 5

Special Consideration for Device Closure:

An ASD with a large septal aneurysm or multifenestrated septum requires careful evaluation by interventional cardiologists before device closure is selected 1:

• These anatomic variants may not be suitable for percutaneous device closure 1
• Surgical closure may be necessary if percutaneous approach is not feasible 1

Management of Embolic Events

If the patient has a history of cerebrovascular events or documented embolic phenomena:

• Long-term anticoagulation is indicated when atrial septal aneurysm is the only identified potential cardiac source of embolism 2
• Consider surgical excision of the aneurysmal portion with pericardial patch repair if recurrent embolic events occur despite anticoagulation 6
• The mechanism may be either primary thrombus formation within the aneurysm or paradoxical embolization through an interatrial communication 2

Critical Pitfalls to Avoid

Do not rely on transthoracic echocardiography alone—TEE is essential for complete evaluation as it detects shunting and complications missed by transthoracic imaging in the majority of cases 2

Do not assume the aneurysm is isolated without TEE evaluation—interatrial shunting is present in 83% of cases when properly assessed with TEE and contrast imaging 2

Do not start empiric anticoagulation without documented embolic events or other clear indication—isolated aneurysms without complications are generally benign and do not require anticoagulation 4

Do not attempt percutaneous device closure without careful evaluation by experienced interventional cardiologists—large septal aneurysms and multifenestrated septa may require surgical rather than percutaneous approach 1

Follow-Up Strategy

For isolated aneurysms under surveillance:

• Periodic clinical assessment for symptoms of embolic events (transient ischemic attacks, stroke) or arrhythmias 3
• Repeat echocardiography if new symptoms develop 3
• Patient education about warning signs of embolic events requiring urgent evaluation 3

For aneurysms with closed ASD:

• Follow standard post-ASD closure protocols including evaluation at 3 months to 1 year for device migration, erosion, or complications 1
• Annual follow-up if repair was performed as an adult and conditions such as pulmonary hypertension, atrial arrhythmias, or ventricular dysfunction persist 1