Libman-Sacks endocarditis is a form of nonbacterial endocarditis that is seen in systemic lupus erythematosus. It was named after American physicians Emanuel Libman and Benjamin Sacks . It is the most common cardiac manifestation of lupus. The vegetations are formed from strands of fibrin, neutrophils, lymphocytes, and histiocytes. The mitral valve is typically affected, and the vegetations occur on the ventricular surface of the valve. Libman-Sacks lesions rarely produce significant valve dysfunction and the lesions only rarely embolize.