Acute mitral regurgitation from ruptured chordae tendineae in systemic lupus erythematosus

A patient with systemic lupus erythematosus developed acute mitral regurgitation due to ruptured chordae tendineae, requiring mitral valve replacement. Typical changes of Libman-Sacks endocarditis were observed in the excised mitral valve. Immunofluorescent studies revealed antinuclear antibody and deposits of immunoglobulins and complement within small vessels.