<prompt> Most common cause of systemic thromboembolism is?Paradoxical emboliIntracardiac muralsAortic aneurysmsUnknown origin  <response>: Most systemic emboli 80 arise from intracardiac mural thrombi; two-thirds of these are associated with left ventricular infarcts and another 25 with dilated left atria e.g.secondary to mitral valve disease. The remainder originate from aortic aneurysms, thrombi overlying ulcerated atherosclerotic plaques, fragmented valvular vegetations, or the venous system paradoxical emboli; 10 to 15 of systemic emboli are of unknown origin. 