Diagnosis of cardiac thrombosis in patients with atrial fibrillation in the absence of macroscopically visible thrombi.

Cardiac thrombosis due to atrial fibrillation (AF) has been recognized as the most common cause of cerebral embolism. However, sometimes no macroscopic thrombus is found at autopsy in the heart of a victim of this type of cerebral embolism. We investigated morphological changes in the left atrial endocardium of 31 patients (including 21 cases with AF) who had died of cerebral embolism.

Effect of recirculation on exacerbation of ischemic vascular lesions in rat brain.

Using electron microscopy, we investigated the small arteries and veins in ischemic lesions induced by occlusion of the ostium of the middle cerebral artery in 42 rats. We observed endothelial denudation in the small arteries of rats receiving occlusion for greater than 6 hours. When the occluding cylinder was removed to allow for reperfusion, however, 2 hours of occlusion was sufficient for endothelial denudation to occur.