Intermittent coronary artery occlusion caused by a floating thrombus in the left coronary sinus of valsalva of a patient with a normal aorta and protein C deficiency.

A floating thrombus in the ascending aorta is an uncommon source of embolism. We report a case in which a floating mass in the left coronary sinus of Valsalva caused intermittent left main coronary trunk occlusion, leading to myocardial ischemia and cardiogenic shock. The mass was surgically resected. Macroscopically, the aortic wall and leaflets were normal. On histologic examination the mass was found to be a thrombus. This patient had a low level of protein C; therefore, it was presumed that the thrombus was due to protein C deficiency.