- Left atrial thrombus
- common in atrial fibrillation or mitral stenosis
- can also develop in myocardial or valvular disease
- Left ventricular thrombus
- more associated with MI (risk of stroke after MI = 12.2 / 1000 MI at 30d)
- ventricular aneurysms develop mural thrombi
- dilated cardiomyopathy (annual risk of embolisation of 1-3.5%, rising to 9% after stroke)
- infective endocarditis – 15-20% incidence of ischemic stroke, higher risk during first week or mitral involvement
- marantic or non bacterial thrombotic endocarditis – also high risk of embolism
- Prosthetic valves
- biological or mechanical valves – 1-4% annual risk of embolisation
- risk higher with mitral prosthetic valves (2-3.5% annually)
- Complex aortic arch atheroma (CAA) protruding >=4mm – RR of recurrent stroke of 1.6-4.3%; higher risk if ulcerated, noncalcified or mobile plaque
- Left atrial thrombus
When to ECHO after stroke?
– ESO recommend echo in selected patients
– ASA guidelines does not have clear recommendations
Pros and Cons: TTE vs TEE
- Easier to perform
- Widely available
- Less sensitive for detection of unknown cardiac sources of emboli
- More expensive
- Requires more training to be performed adequately
- Identifies possible cardiac sources of embolism in >50% of patients without clinically known heart disease (vs 25% with TTE+bubble)
**Sensitivity for detection of LV thrombi similar, but detection of LAT, PFO and vegetation’s favors TEE.
TEE considered safe, with 0.025 complication rate, though cases of paradoxical air emboli have been published and risks of hypotension during procedure should be considered.
- No data to support optimal approach.
- If (+) heart disease – TTE has superior yield
- Age should not be used as an exclusion criterion
- Use TEE in patients who are candidates for oral anticoagulation after routine diagnostics cannot find an etiology.
- Select patients based on complete cardiovascular history and PE
- Accurate cardiac evaluation to detect underlying heart disease
- Neuro evaluation reveals suspicion of emboli stroke
- All stroke patients get an initial EKG adn serial EKG and 48 hour telemetry
- Neuroimaging (MRI) to reveal patterns of ischemia suggestive of embolic stroke of cardiac origin
- US of intracranial and extracranial arteries or MRA / CTA to rule out large vessel disease
- TCD first line to diagnose right to left shunt (RLS), HITS monitoring useful in certain patients
- No further cardiac studies if not eligible for oral anticoagulation
- All patients with undetermined stroke after these studies, with an emboli pattern should receive TTE,followed by TEE if nondiagnostic.
- In patients without previous heart disease, with RLS on TCD or where other sources of emboli are more relevant, may be more cost effective to directly proceed with TEE
- No etiology found but with evidence of emboli stroke where paroxysmal atrial fibrillation suspected should receive prolonged rhythm monitoring with Holter, loop recorders.
Ustrell, X., & Pellise, A. (2010). Cardiac Workup of Ischemic Stroke. Current Cardiology Reviews, 6(3), 175-183. doi: 10.2174/157340310791658721