What is the management for a patient with a confirmed interatrial shunt, such as a patent foramen ovale, demonstrated by early passage of bubbles after injection of agitated saline contrast?

Management of Interatrial Shunt Detected by Agitated Saline Contrast

For patients with a confirmed interatrial shunt, such as a patent foramen ovale (PFO), antiplatelet therapy is recommended as first-line management unless specific indications for PFO closure or anticoagulation exist. 1

Diagnostic Confirmation and Assessment

• Timing of bubble appearance is critical:

  • Early appearance (3-8 cardiac cycles): Confirms interatrial shunt (typically PFO) 2
  • Delayed appearance (>8 cardiac cycles): Suggests intrapulmonary shunt 2

• Shunt quantification:

  • Grade 1: <30 bubbles
  • Grade 2: Moderate filling
  • Grade 3: Complete opacification of left atrium 1, 2

• Additional imaging needed:

  • Transesophageal echocardiography (TEE) for detailed assessment of atrial septal anatomy 1
  • Assessment for atrial septal aneurysm (increases embolic risk) 1

Management Algorithm

1. For Cryptogenic Stroke Patients with PFO:

• First-line approach: PFO closure plus antiplatelet therapy

  • Strongest indication: Age ≤60 years with cryptogenic stroke, large right-to-left shunt, atrial septal aneurysm, and no atrial fibrillation 1, 3
  • Reduces recurrent stroke risk by 8.7% over 5 years 1
  • Note: 3.6% risk of device/procedure-related adverse events 1

• If PFO closure contraindicated/unacceptable:

  • Anticoagulation preferred over antiplatelet therapy alone 1

2. For Non-Stroke Patients with PFO:

• Standard approach: Antiplatelet therapy 1

  • Typically aspirin or clopidogrel if aspirin intolerant

• Consider anticoagulation if:

  • High risk for cardiac embolism (e.g., paroxysmal atrial fibrillation, recent MI) 1
  • Deep vein thrombosis with PFO (increased paradoxical embolism risk) 4

3. For Patients with Pulmonary Embolism and PFO:

• More aggressive management warranted:
  • PFO presence increases death risk (RR 2.4) and ischemic stroke risk (RR 5.9) 2
  • Consider anticoagulation over antiplatelet therapy 1, 4

Special Considerations

• Residual shunt after PFO closure:

  • Monitor with follow-up echocardiography at 3 and 12 months 5
  • If significant residual shunt persists, consider second closure device 6

• Procedural considerations for PFO closure:

  • Typically performed with catheter insertion at groin under local anesthesia
  • Usually requires overnight hospital stay
  • Most activities can be resumed within days, full recovery within weeks 1

Common Pitfalls to Avoid

1. Unnecessary screening: Many bubble studies are performed in patients with identifiable stroke causes where PFO is likely incidental 7

2. Overlooking alternative diagnoses: Ensure comprehensive stroke workup before attributing to PFO

3. Failure to assess DVT: Patients with PFO and paradoxical embolism should be evaluated for DVT 4

4. Ignoring atrial septal aneurysm: Its presence significantly increases embolic risk and may influence management decisions 1

5. Inadequate follow-up: Patients with PFO closure require monitoring for device complications and residual shunt 5, 6