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← Section VI · Miscellaneous Topics (Role of Echo)
VI.B

Cardiac Sources of Embolism (PFO, ASA, SEC, Aortic Atheroma, etc)

8 cards

Notes

Major cardioembolic sources

Left atrial appendage / LA thrombus

  • Atrial fibrillation (nonvalvular AF, esp. with high CHA₂DS₂-VASc).
  • Valvular AF (mitral stenosis).
  • LAA emptying velocity < 20 cm/s + severe SEC → very high risk.

LV thrombus

  • Post-anterior MI with apical akinesis.
  • Dilated cardiomyopathy.
  • Apical HCM.
  • LV noncompaction.
  • Contrast improves detection when apex is poorly seen.

Patent foramen ovale (PFO)

  • Prevalence ~25 % of adults.
  • Increased risk of cryptogenic stroke, especially with ASA or large right-to-left shunt.
  • Diagnosis: agitated saline contrast with Valsalva release - bubbles in LA within ≤ 3 cardiac cycles.
  • Closure indicated for cryptogenic stroke in patients 18–60 with a high-risk PFO (recent data support younger patients).

Atrial septal aneurysm (ASA)

  • Excursion of atrial septum > 10 mm from mid-plane, or 15 mm total.
  • 30–50 % of ASAs have coexistent PFO.
  • Independent stroke risk factor (RoPE score integrates both).

Aortic atheroma

  • Complex atheroma: ≥ 4 mm thickness, mobile debris, ulceration.
  • Descending aorta best imaged on TEE.
  • Independent predictor of cryptogenic stroke.

Vegetations (endocarditis)

  • Left-sided → systemic embolism; right-sided → pulmonary embolism.
  • Vegetation > 10 mm, high mobility → increased embolic risk.

Cardiac tumor

  • Left atrial myxoma - classic embolic source.
  • Papillary fibroelastoma (aortic valve) - small but high embolic risk.

Spontaneous echo contrast (SEC)

  • Swirling smoke-like echoes in LA/LAA reflecting slow flow.
  • Marker of stasis; associated with prior CVA and future embolic events.

Diagnostic approach to cryptogenic stroke

  • TTE first for LV thrombus, valve, and gross function.
  • TEE for LAA thrombus, PFO/ASA, aortic atheroma, vegetations.
  • Agitated saline contrast with Valsalva for PFO.

PFO closure criteria

  • Cryptogenic stroke (excluded other causes).
  • Age 18–60 (older data; newer trials expand upper age).
  • PFO confirmed by echo with bubble study.
  • High-risk features: large shunt, associated ASA.
  • Recurrent stroke on medical therapy.

Cards

  • basicVI.B-001
    Approximate adult prevalence of patent foramen ovale?
    → ~25% (about 1 in 4 adults). Not all PFOs cause clinical events.
  • basicVI.B-002
    Define atrial septal aneurysm.
    → Excursion of the atrial septum > 10 mm into either atrium from the mid-septal plane, or a total excursion of 15 mm. Coexists with PFO in 30–50%.
  • basicVI.B-003
    State the four criteria that define a 'complex' aortic atheroma on TEE.
    → 1) Thickness ≥ 4 mm. 2) Mobile debris on the atheroma. 3) Ulcerated surface. 4) Location in aortic arch or ascending aorta. Complex atheroma is an independent risk factor for cryptogenic stroke.
  • basicVI.B-004
    Which primary cardiac tumor is the most classic cardioembolic source?
    → Left atrial myxoma. Fragments can embolize systemically, causing stroke or peripheral emboli. Papillary fibroelastoma (aortic valve) is also a well-recognized embolic source despite small size.
  • basicVI.B-005
    For which patients should PFO closure be considered after a stroke?
    → Age 18–60 (older data; newer trials extend upper age) with confirmed PFO, cryptogenic ischemic stroke after exclusion of other causes, and preferably high-risk features (large shunt, associated ASA, or recurrent stroke on medical therapy).
  • basicVI.B-006
    State the RoPE score's purpose.
    → The Risk of Paradoxical Embolism (RoPE) score estimates the probability that a PFO is causally related to a cryptogenic stroke, using age, cortical infarct, and vascular risk factors.
  • basicVI.B-007
    When should you strongly consider LV apical thrombus in a patient with a recent stroke?
    → After a large anterior MI with apical akinesis, in dilated cardiomyopathy, apical HCM, or LV noncompaction. Use contrast for LV opacification when the apex is poorly visualized.
  • basicVI.B-008
    Which pulmonary vascular malformation should be suspected when bubbles from a right-sided contrast study appear in the LA after > 3 cardiac cycles?
    → Pulmonary arteriovenous malformation — as seen in hereditary hemorrhagic telangiectasia (HHT, Osler-Weber-Rendu). Represents an intrapulmonary rather than intracardiac shunt.