<s>[INST] context: She developed bacterial septicemia followed by infective endocarditis of the mitral valve. Thus she has a high risk for developing complications of infective endocarditis. Such valvular vegetations are destructive of the valve. The impaired functioning of the mitral valve (most likely regurgitation) would give rise to left atrial dilation and left ventricular failure with pulmonary edema. Septic emboli from the mitral valve vegetation could reach the systemic circulation and give rise to abscesses. The infection of an arterial wall can weaken the wall, resulting in aneurysm formation and the potential for rupture. Dilated cardiomyopathy may be due to chronic alcoholism, or it may be idiopathic. It may be familial, or it may follow myocarditis, but it is not a direct complication of infective endocarditis. Myxomatous degeneration of the mitral valve results from a defect in connective tissue, whether well-defined or unknown; the mitral valve leaflets are enlarged, hooded, and redundant. Lesions on the right side of the valve can produce septic emboli that involve the lungs, but vegetations on the left side embolize to the systemic circulation, producing lesions in the spleen, kidneys, or brain. Pulmonary abscesses can occur from right-sided infective endocarditis because septic emboli pour into the pulmonary arterial circulation. [/INST] question: A 26-year-old woman has had a fever for 5 days. On physical examination, her temperature is 38.2deg C, pulse is 100/min, respirations are 19/min, and blood pressure is 90/60 mm Hg. A cardiac murmur is heard on auscultation. Her sensorium is clouded, but there are no focal neurologic deficits. Laboratory findings include hemoglobin, 13.1 g/dL; platelet count, 233,300/ mm3; and WBC count, 19,200/ mm3. Blood cultures are positive for gram-positive bacteria. Urinalysis shows hematuria. An echocardiogram shows 1.5-cm vegetation on the mitral valve. Which of the following conditions is this patient most likely to develop? | options: A: Cerebral arterial mycotic aneurysm B: Dilated cardiomyopathy C: Myxomatous mitral valve degeneration D: Pericardial effusion with tamponade | answer: A </s>