Prevention of Cardioembolic Stroke

Abstract

Cardiac causes of ischemic stroke lead to severe neurological deficits from large intracranial artery occlusion compared to small vessel ischemic stroke. The most common cause of cardioembolic stroke is atrial fibrillation (AF), which has an increasing incidence with age. AF stroke trials demonstrate that anti-coagulation is superior to anti-platelet therapy in terms of ischemic stroke prevention. Recently, warfarin was compared with dabigatran, an oral, direct thrombin inhibitor, and was found to be at least equally effective in reducing ischemic stroke with less intracranial bleeding risk. Future research is investigating other direct thrombin inhibitors as potential alternatives to warfarin, which has a narrow therapeutic index, requires frequent blood monitoring, has multiple drug interactions, and a higher rate of intracranial bleeding. Other causes of cardioembolic stroke include myocardial infarction, left ventricular thrombus, reduced ejection fraction, valvular abnormalities, and endocarditis. Patent foramen ovale is a common finding on echocardiograms in patients with and without stroke (up to 20% of the population), and it is a controversial source of cryptogenic stroke. The best way to prevent cardioembolic stroke remains early detection and treatment of AF, and treating the underlying stroke mechanism. Cardiac magnetic resonance imaging is an emerging technology and reveals some sources of cardiac embolism missed by echocardiography, and might provide an additional diagnostic tool in investigating cardioembolic stroke.

Physician's Fear of Anticoagulant Therapy in Nonvalvular Atrial Fibrillation

“… 4 An estimated 69,165 of these strokes are attributable to AF. 5 , 6 Every hour, approximately 8 Americans suffer from an ischemic stroke arising from AF. 5 , 6 Currently, validated risk stratification schemes such as CHADS 2 and CHA 2 DS 2 -VASc, based on other predisposing conditions, facilitate stroke prediction in patients with AF (Table 1 ).…”

Cardiac MRI Improves Identification of Etiology of Acute Ischemic Stroke

“…Its role in the assessment of CAE strokes has been suggested previously [13,14], however, except for three small limited studies, which looked at specific pathologies [15,16,17], CMR's utility to detect all sources of cerebral embolism is not well established. We evaluated the feasibility of using CMR to assess cardiac and aortic sources of acute cerebral embolism.…”

A cardiac cause for deafness

“…Characteristic features of cardioembolic strokes include infarcts of multiple discrete vascular territories, and alternating right and left hemispherical involvement 2. Recognition of the cardioembolic stroke is essential not only because of the morbidity associated with them, but also because of the significant reduction in the risk of stroke with appropriate antithrombotic therapy 1. The patient described in this report developed bilateral temporal lobe infarcts after defaulting on standard antiatherosclerotic medications including low-dose aspirin.…”

“…Cardioembolic strokes account for up to 20% of all ischemic strokes, but often produce disproportionately greater disability than non-embolic strokes due to their potential for involving larger intracranial arteries 1. Characteristic features of cardioembolic strokes include infarcts of multiple discrete vascular territories, and alternating right and left hemispherical involvement 2.…”