Embolism cardioembolism

Early Recurrence Rates in Cardioembolic Stroke The primary rationale for acute antithrombotic therapy in cardioembolic stroke, including that associated with AF, is prevention of early recurrence secondary to further embolism. 

Cardioembolism Cardioembolism accounts for approximately 30% of all stroke and 25-30% of strokes in the young (age <45 years)." AF accounts for a large proportion of these strokes (15-25%). Symptoms may be suggestive, but they are not diagnostic. Repetitive, stereotyped, transient ischemic attacks (TIAs) are unusual in embolic stroke. The classic presentation for cardioembolism is the sudden onset of maximal symptoms. The size of the embolic material determines, in part, the course of the embolic material. Small emboli can cause retinal ischemic or lacunar symptoms. Posterior cerebral artery territory infarcts, in particular, are often due to cardiac embolism. This predilection is not completely consistent across the various cardiac structural abnormalities that predispose to stroke, and may be due to patterns of blood flow associated with specific cardiac pathologies. 

In the second part we will describe the clinical MR features of embolic stroke, with emphasis on cardioembolic stroke. 

MCA infarcts are mainly caused by cardioembolism, internal carotid artery (ICA) thrombosis, dissection or embolism and rarely (in Caucasians) by intrinsic MCA disease. MCA atherothrombotic territory infarctions related to intrinsic MCA disease often cause concomitant small cortical (territorial or borderzone) and subcortical infarcts (Min et al. 2000). 

Aphasia and neglect can be found following respectively dominant and non-dominant anterior choroidal artery infarcts. Anterior choroidal artery infarcts usually cause the classical 3H syndrome hemiparesis, hemihypesthesia, hemianopia. Pure motor hemiparesis and isolated hemianopia can also occur (Han et al. 2000). Anterior choroidal artery territory infarcts are rarely caused by small vessel occlusion. In general they are caused by cardioembolism or large artery disease with occlusion or artery-to-artery embolism (Leys et al. 1994). 

Approximately 20% of ischemic stroke is cardioembolic. There are a large number of potential cardiac sources of embolism (Table 6.3) but it may be difficult to be certain whether an identified putative embolic source is the cause of a stroke, particularly if there are alternative causes such as coexistent large artery disease, or if the stroke is lacunar and unlikely to be caused by cardiac embolism. 

Cardioembolic stroke—An ischemic stroke thought to be caused by an embolism arising from the heart. Cardioembolic stroke can be assumed in patients with significant cardiovascular disease including atrial fibrillation, dilated cardiomyopathy, prosthetic valves, recent MI and patent foramen ovale. 

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