Cardioembolic stroke from atrial septal aneurysm.

Atrial septal aneurysm is an uncommon occult cardiac source of cerebral embolism. It is usually asymptomatic, and clinical cardiologic examination and electrocardiography fail to reveal its presence. We report a case of a 34-year-old woman with sudden right hemiplegia and aphasia from occlusion of the left carotid siphon in whom an atrial septal aneurysm was detected by two-dimensional echocardiography. The absence of atherosclerotic risk factors and vascular lesions proximal to the carotid occlusion strengthened a causal relation between atrial septal aneurysm and cerebral infarction. Consequently, two-dimensional echocardiography may be advisable in every patient with unexplained ischemic stroke to detect possible occult embolic cardiac abnormalities.