A 30-year-old woman presents with a hea murmur. There is a history of recurrent episodes of ahritis, skin rash and glomerulonephritis. Blood cultures are negative. Laboratory tests for antinuclear antibodies (ANA) and anti-double-stranded DNA are positive. Which of the following is the most likely cause of hea murmur in this patient?

In patients with systemic lupus erythematosus, endocarditis is the most striking cardiac lesion, termed Libman-Sacks endocarditis. Libman-Sacks endocarditis(LSE) is a form of non-bacterial endocarditis that is seen in association with systemic lupus erythematosus (SLE) Nonbacterial vegetations are seen on the undersurface of the mitral valve close to the origin of the leaflets from the valve ring (Libman-Sacks endocarditis). There is fibrinoid necrosis of small vessels with focal degeneration of interstitial tissue. Rheumatic fever is not commonly associated with ANAs seen in this case.