Flow and velocity during autoregulation testing in humans.

Chimowitz et al refer to preliminary data 4 suggesting increased fibrinogen in patients with SEC. We have shown 5 that fibrinogen is an independent risk factor for left atrial SEC in patients with nonvalvular atrial fibrillation and that both fibrinogen and SEC are independently associated with embolic events. The relationship between SEC and embolism therefore appears complex, comprising both hemostatic and hemodynamic abnormalities and both cardioembolic and other mechanisms of stroke. WM. Left atrial spontaneous echo contrast is highly associated with previous stroke in patients with atrial fibrillation or mitral stenosis. Left atrial spontaneous echo contrast: a clinical and echocardiographic analysis.nostic implications of left atrial spontaneous echo contrast in non-valvular atrial fibrillation. J Am Coll Cardiol. In press. Spontaneous echo contrast, ischemic stroke, and risk of current stroke. Walsh WF. Hematologic correlates of left atrial spontaneous echo contrast and thromboembolism in nonvalvular atrial fibrillation. Response In a prospective study, groups of patients with and without a particular risk factor are followed over time to determine the rates at which they develop a specific disease. 1 Neither our study 2 nor the one by Black et al 3 followed patients with and without SEC to determine their rates of cerebral or systemic embolism. In both studies only embolic events that occurred before identification of SEC were documented. As such, neither of these studies provide a prospective evaluation of the embolic risk posed by SEC. The fact that patients were identified for the study by Black et al at the time of transesophageal echocardiography rather than by review of the echocardiography reports is not a sufficient condition to ensure a prospective study. The recent studies on SEC by Black et al that are referenced in their letter are of considerable interest. We look forward to publication of the study on future cardiac events in patients with SEC, which to our knowledge is the first prospective evaluation of the embolic risk associated with SEC. WM. Left atrial spontaneous echo contrast is highly associated with previous stroke in patients with atrial fibrillation or mitral stenosis. Left atrial spontaneous echo contrast: a clinical and echocardiographic analysis. It may be unusual to write a letter to the editor referring to an abstract rather than to an original publication. Nevertheless, the summary of the paper read by Newell et al at the 19th International Joint Conference on Stroke and Cerebral Circulation and published in the January issue …