Case presentation
A diabetic 26-year-old man was admitted to our center due for prolonged fever. He had no history of rheumatic or congenital heart disease. He had been well until three weeks ago, when he began to have fatigue and general malaise, as well as loss of appetite. At admission, the patient was febrile at 39°C and tachycardic. His lung sounds were clear, and no cardiac murmur was audible. There were no signs of heart failure.
The laboratory tests showed an inflammatory syndrome. An echocardiographic evaluation revealed a normal global systolic left ventricular function, no valvular disease but we noted a 15 x 11 mm mobile oscillating large mass with anechogenic content attached to the mitral anterolateral papillary muscle (Figure 1 ).
Despite the intravenous antibiotic therapy, fever had persisted. A thoraco-abdominal computed tomography revealed multiple hypodensities of the brain, the liver and the spleen consistent with septic emboli. The usual blood cultures were negative and these results were attributed to prior antibiotics. Few days after hospitalization, the patient’s clinical condition worsened and pulmonary congestion appeared suddenly. The physical examination revealed a new pansystolic murmur consistent with mitral regurgitation. There was no electrocardiographic change suggesting an acute or subacute myocardial infarction.
Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) examinations were repeated. Echocardiographic studies showed a hyperdynamic left ventricle with no regional wall-motion abnormality but we noticed severe mitral regurgitation with a prolapse of the anterior mitral valve due to the rupture of the mitral anterolateral papillary muscle, which explained the patient clinical status (Figure 2 ). The diagnosis of IE complicated by severe mitral regurgitation was established. The patient was admitted to intensive care unit for stabilization with medical therapy. Then, he underwent urgent prosthetic mitral valve replacement. On surgical inspection, total complete rupture of the tip of anterolateral papillary muscle was found (Figure 3 ).
The histologic examination of the resected tissues revealed a non-specific inflammation with fibrosis. The valve culture was negative. Given the histologic examination results, the diagnosis was a mitral valve IE complicated by anterolateral papillary muscle rupture due to direct germ invasion. After 8 weeks of IV antibiotic therapy, the patient was uneventfully discharged.