What is the management of an interatrial aneurysm?

Management of Interatrial Aneurysm

The management of interatrial aneurysm should include anticoagulation therapy for patients with documented thrombus or previous thromboembolic events, and surgical intervention should be considered for patients with embolic complications, particularly those with cerebral symptoms.

Diagnosis and Assessment

• Imaging Modalities:

  • Transesophageal echocardiography (TEE) is superior to transthoracic echocardiography for diagnosis of interatrial septal aneurysms 1
  • TEE can accurately visualize the aneurysm's size, mobility, and relationship to surrounding structures 2
  • Cardiac magnetic resonance imaging may be used but may underestimate the size of the aneurysm 2

• Key Diagnostic Features:

  • Hemispherical bulge in the mid-portion of the interatrial septum
  • Mobile structure with to-and-fro motion between the atria during cardiac cycles 3
  • May mimic right atrial tumors or cystic masses 2

Risk Stratification

• High-Risk Features:
  • History of embolic events (28-52% of patients with interatrial septal aneurysms have embolic events) 4
  • Patent foramen ovale (present in 87% of patients with interatrial septal aneurysms) 1
  • Large size or high mobility of the aneurysm
  • Presence of thrombus within the aneurysm 5

Treatment Algorithm

1. Medical Management

• Anticoagulation:
  • Indicated for patients with:
    • Documented thrombus within the aneurysm
    • Previous thromboembolic events
    • High-risk features (large aneurysm with high mobility)
  • Options include:
    • Warfarin (target INR 2-3)
    • Direct oral anticoagulants (DOACs)

2. Surgical Management

• Indications for Surgery:

  • History of embolic events, particularly cerebral symptoms 4
  • Large aneurysm with high risk of complications
  • Presence of thrombus resistant to anticoagulation
  • Concomitant cardiac pathology requiring surgery

• Surgical Approach:

  • Performed under extracorporeal circulation
  • Excision of the aneurysmal part of the interatrial septum
  • Replacement with a pericardial patch 4
  • Complete obliteration of the aneurysm should be the goal of any interventional approach 6

3. Follow-up

• Regular clinical assessment for symptoms of embolism
• Periodic echocardiographic evaluation to monitor for:
  • Changes in aneurysm size or mobility
  • Development of thrombus
  • Effectiveness of surgical repair

Special Considerations

• Mimicry of Other Conditions:

  • Interatrial septal aneurysms can mimic cardiac tumors (particularly myxomas) or thrombi 5, 2
  • Careful imaging assessment is essential for correct diagnosis

• Association with Other Cardiac Abnormalities:

  • Patent foramen ovale (significantly higher prevalence in patients with interatrial septal aneurysms) 1
  • Other congenital heart defects
  • Valvular heart disease

Pitfalls and Caveats

• Transthoracic echocardiography alone may miss the diagnosis (detected only 28% of cases in one study) 1
• Contrast studies should be performed to assess for patent foramen ovale
• Surgical treatment should be considered even in isolated interatrial septal aneurysms with embolic complications, as this may prevent recurrent embolic events 4
• Closed interatrial septum aneurysms filled with blood can be mistaken for tumors or thrombi, leading to unnecessary interventions if not properly diagnosed 5