What is the management plan for a patient with a hypermobile septal aneurysm?

Management of Hypermobile Septal Aneurysm

The management of a hypermobile septal aneurysm should focus on risk assessment for potential complications, particularly thromboembolism, and appropriate treatment based on symptomatology and associated cardiac conditions.

Clinical Assessment and Diagnosis

• Hypermobile septal aneurysm (also called atrial septal aneurysm) appears as a localized bulging of the interatrial septum that may protrude into the right atrium only or move between both atria during the cardiac cycle 1
• Transthoracic echocardiography (TTE) is recommended as the initial diagnostic tool, but transesophageal echocardiography (TEE) provides superior visualization and should be performed if TTE is inconclusive 2, 3
• TEE can better identify important features such as:
  • Multiple fenestrations within the aneurysm
  • Presence of thrombus within the aneurysm
  • Associated interatrial shunting 3

Risk Stratification

• Patients with hypermobile septal aneurysm have an increased risk of thromboembolic events, particularly stroke 3
• Risk factors for thromboembolism in patients with septal aneurysms include:
  • Thickening of the aneurysmal membrane ≥5 mm (significantly associated with cerebrovascular events) 3
  • Presence of interatrial shunting (patent foramen ovale) 2
  • History of previous embolic events 1, 3

Management Approach

For Asymptomatic Patients

• Regular cardiac monitoring with TTE is recommended every 1-2 years to assess for changes in size, development of complications, or associated cardiac conditions 2
• Screening for potential interatrial shunting using contrast echocardiography or color Doppler is important, as shunts are present in up to 83% of patients with septal aneurysms when assessed by TEE 3

For Patients with History of Embolic Events

• Long-term anticoagulation therapy is indicated in patients with hypermobile septal aneurysm who have experienced a thromboembolic event 3
• The mechanism of embolization may be either:
  • Primary thrombus formation within the aneurysm
  • Paradoxical embolization through an associated interatrial communication 3

For Patients with Associated Cardiac Conditions

• If the septal aneurysm is associated with significant atrial septal defect:
  • Consider device closure or surgical repair based on defect size and location 4
  • Post-procedure follow-up should include TTE at 1 month, 3-6 months, and 1 year 4
• If associated with ventricular septal defect:
  • Surgical resection of the aneurysm and patch closure of the defect is recommended, even in asymptomatic patients, to prevent complications such as tricuspid insufficiency, aortic valve prolapse, right ventricular outflow tract obstruction, rupture, and bacterial endocarditis 5

For Patients with Complications

• For right ventricular outflow tract obstruction caused by the aneurysm:
  • Surgical intervention may be necessary to relieve obstruction 6
• For thrombus formation within the aneurysm:
  • Anticoagulation and consideration of surgical resection 7, 3

Special Considerations

• Hypermobile septal aneurysm may be a coincidental finding during cardiac surgery for other conditions but should not be ignored due to potential complications 7
• Direct suture repair of associated defects has been associated with recurrence of aneurysm; patch closure is preferred 5
• Patients should be educated about symptoms that warrant urgent evaluation, such as neurological deficits, chest pain, or syncope 4

Follow-up Recommendations

• More frequent follow-up is recommended for patients with:
  • History of embolic events
  • Associated structural heart disease
  • Evidence of thrombus formation
  • Significant interatrial shunting 4
• Follow-up imaging should include assessment of:
  • Aneurysm size and mobility
  • Presence of thrombus
  • Associated shunting
  • Right and left ventricular function 4