Libman–Sacks endocarditis (often misspelled Libmann-Sachs) is a form of nonbacterial endocarditis that is seen in systemic lupus erythematosus. It is one of the most common cardiac manifestations of lupus (the most common being pericarditis).
The vegetations are small and formed from strands of fibrin, neutrophils, lymphocytes, and histiocytes. The mitral valve is typically affected, and the vegetations occur on the ventricular and atrial surface of the valve. Libman-Sacks lesions rarely produce significant valve dysfunction and the lesions only rarely embolize.