Cryptogenic Stroke: Search Your Heart!

Abstract

About 30-40% of all ischemic strokes are classified as cryptogenic because no well defined cause can be identified. Without a known cause, the treatment is arbitrary, usually defaulting to antiplatelet therapy and the risk of future stroke is uncertain. Cryptogenic stroke is an imprecise term that includes four subcategories: strokes without a sufficient evaluation, those with a thorough but seemingly negative evaluation, those that don't strictly meet criteria for other established causes, and those with multiple competing causes. High risk etiologies that are often missed include aortic arch atherosclerosis, paroxysmal atrial fibrillation, and akinetic left ventricular segments. The risk related to a low ejection fraction or an enlarged left atrium has been incompletely studied. The role of patent foramen ovale in the pathogenesis of cryptogenic stroke remains complex and unresolved. Rare causes often are not considered at all. Specific attention to detecting these cardiac problems with echocardiography and prolonged rhythm monitoring could cut the proportion of cryptogenic strokes by as much as half and result in improved prevention of recurrent stroke.