Association between paroxysmal atrial fibrillation and the left atrial appendage ejection fraction during sinus rhythm in the acute stage of stroke: a transesophageal echocardiographic study.

Background: This study aimed to investigate whether left atrial appendage (LAA) dysfunction evaluated by transesophageal echocardiography (TEE) during sinus rhythm is predictable of paroxysmal atrial fibrillation (PAF) as an embolic source in the acute stage of stroke.

Methods And Results: We measured and analyzed LAA flow velocity (LAA-FV) and LAA ejection fraction (LAA-EF) in 300 acute ischemic stroke patients by TEE. We divided the acute ischemic stroke patients into 3 groups.

Isolated anterior cerebral artery territory infarction: dissection as an etiological mechanism.

Background: Intracranial arterial lesions are important causes of ischemic stroke, particularly in the Asian population. Of the intracranial lesions, the etiology of isolated anterior cerebral artery (ACA) territory infarction is not fully elucidated. The purpose of this study was to determine the etiological and clinical characteristics of patients with isolated ACA territory infarction, especially those with ACA dissection.

Paradoxical cerebral embolism causing internal carotid artery occlusion.

Paradoxical cerebral embolism (PCE) is defined to be a pathological condition in which emboli originating from the venous system reach the cerebral arterial circulation via the right-to-left (R-L) shunt. In patients with PCE, emboli originating from the venous system most commonly pass through the patent foramen ovale during Valsalva-provoking activities which increase the right atrial pressure above the left atrial pressure. The size of cerebral infarction caused by PCE is generally small, since the size of emboli which can pass through the R-L shunt is small.

Microembolic signals within 24 hours of stroke onset and diffusion-weighted MRI abnormalities.

Background: The clinical relevance of the microembolic signals (MES) detected by transcranial Doppler sonography (TCD) in acute stroke remains unclear. In a prospective study the authors analyzed the relationship between MES and the findings on diffusion-weighted magnetic resonance imaging (DWI) in acute stroke patients.

Methods: We performed TCD for a period of 30 min to detect MES in patients within 24 h of stroke onset, and DWI was done within the initial 7 days.