Acute papillary muscle infarction and rupture in the puerperium complicating Libman-Sacks endocarditis in a patient with systemic lupus erythematosus and antiphospholipid syndrome: a case report.

Background: Acute heart failure caused by severe mitral regurgitation (MR) due to papillary muscle rupture has been described in the puerperium by case reports; however, the majority of cases of papillary muscle rupture are caused by myocardial infarction. We describe papillary muscle rupture occurring in the postpartum period in a patient with systemic lupus erythematosus (SLE), antiphospholipid syndrome (APLS), and chronic Libman-Sacks endocarditis and explore the multifactorial nature of the papillary muscle infarction and rupture in the setting of postpartum fluid shifts, chronic myocardial injury from Libman-Sacks, and high thrombotic risk.

Case Summary: A 29-year-old woman presented with acute heart failure 2 weeks' postpartum and was found to have acute MR due to a flail leaflet caused by papillary muscle rupture. She proceeded to emergency surgery with mitral valve (MV) replacement and the histology revealed evidence of chronic Libman-Sacks endocarditis and papillary muscle infarction with thrombi in the intramyocardial arteries.

Discussion: This is the second case report of papillary muscle rupture in the puerperium in a patient with SLE in the literature, the other case was caused by catastrophic APLS. However, in this case, the cause of the rupture is likely to be multifactorial; as a consequence of thrombosis in the microvasculature causing isolated papillary muscle ischaemia, and fibrosis of the muscle due to chronic Libman-Sacks endocarditis resulting in limited pliability which caused rupture of the papillary muscle when faced with the added stress of increased volume that occurs in the puerperium.