Embolic Stroke

Emily ChangPGY-3

May 4, 2010

Definition

Particles of debris that originate from another source that lead to blockage of arterial perfusion of a region in the brain

Approximately 20-30% of ischemic strokes are cardioembolic

Generally worse prognosis than thrombotic strokes as the area infarcted is usually larger due to large emboli

What to Look For

Cardiac arrhythmias

Cardiac murmurs

Signs of CHF

Recent MI

Concomitant diseases (SLE, endocarditis, neoplasias)

Other signs of systemic embolism

Time course

Usually abrupt onset that is maximal at the start

Symptoms may clear entirely since the emboli can migrate and lyse

Multiple sites in different vascular beds may be affected leading to different symptoms at different times

Types

known cardiac source

possible cardiac or aortic source based on TTE or TEE

arterial source

unknown source with negative tests for embolic sources

Major risk sources

Atrial fibrillation (accounts for 50%)Rheumatic valve diseaseBioprosthetic and mechanical heart valvesAtrial or ventricular thrombusSSSSustained atrial flutterMI within one monthCHF with EF<30%Dilated CMEndocarditisLeft atrial myxoma

Minor risk sources

Patent Foramen Ovale

Atrial Septal Aneurysms

Mitral Valve Prolapse

Calcific Aortic Valve or Bicuspid Aortic Valve

Mitral Annular Calcification

Fibroelastomas (benign tumors on valves)

Lambi excrescences (filliform outgrowths from free borders of valves)

Treatment

Primary prophylaxis depends on the particular risk factor but centers primarily around anti-coagulation, especially in the high-risk group (except for endocarditis and myxoma)

Primary prophylaxis for medium or low risk factors is less clear as benefit of anti-coagulation is not yet proven

Treatment of acute embolic stroke depends on the source of the stroke but centers primarily around anti-coagulation

References

Caplan, Louis. “Etiology and classification of Stroke.” Up to Date Online. Web. 30 Sept 2009.

Schneck, Michael. “Cardioembolic stroke.” emedicine. WebMD. Web. 13 Feb 2008.

Alguire, Patrick; Epstein, Paul. MKSAP 14. ACP. 2006.