Severe Mitral Regurgitation As a Result of Rupture of Mitral Valve Chordae Tendineae in a Patient With Graves Disease

Mitral valve prolapse is a common disorder, but severe mitral regurgitation (MR) as a result of rupture of mitral valve chordae tendineae is a rare manifestation of thyrotoxic heart disease. There are limited reports with respect to the onset of severe MR as a complication of Graves disease. We report a case of a 60-year-old woman with Graves disease and thyroid-associated ophthalmopathy as her past history. She had signs of congestive heart failure, a loud murmur as a result of MR, clinical cardiomegaly, and peripheral edema. Echocardiographic and angiographic data were consistent with moderate to severe MR. She also had thyrotoxicosis caused by the recurrence of Graves disease. She was taking methiamazole, a beta-blocker, hydrocortisone, and potassium iodide. Ultimately, thyroidectomy was performed to improve her hyperthyroid state. After normalization of her thyroid status, she continued to have moderate to severe MR, and mitral valve repair was performed. The present case had severe MR as a result of rupture of mitral valve chordae tendineae, which is considered rare in a patient with Graves disease.