<prompt> Most aerial emboli originate from which one of the following sites?Cardiac valveLeft atriumLeft ventricleThoracic aoa  <response>: Most aerial emboli originate in the hea. The most common intracardiac site is the left atrium, in which thrombi form because of stasis in patients with atrial fibrillation, mitral valvular disease, or both. Left ventricular thrombi are a potential source of embolism in patients with myocardial infarction, left ventricular aneurysm, congestive hea failure, or cardiomyopathy. 