08-05-2008, 07:52 PM
A 25-year-old previously healthy woman has had worsening fatigue with dyspnea, palpitations, and fever over the past week. On physical examination her vital signs show T 38.9 C, P 103/minute, RR 30/minute, and BP 95/65 mm Hg. Her heart rate is slightly irregular. An ECG shows diffuse ST-T segment changes. A chest x-ray shows mild cardiomegaly. An echocardiogram shows slight mitral and tricuspid regurgitation but no valvular vegetations. Laboratory studies show a troponin I of 12 ng/mL. She recovers over the next two weeks with no apparent sequelae. Which of the following laboratory test findings best explains the underlying etiology for these events?
A Anti-streptolysin O titer of 1:512
B Total serum cholesterol of 537 mg/dL
C Coxsackie B serologic titer of 1:160
D Blood culture positive for Streptococcus, viridans group
E ANCA titer of 1:80
A Anti-streptolysin O titer of 1:512
B Total serum cholesterol of 537 mg/dL
C Coxsackie B serologic titer of 1:160
D Blood culture positive for Streptococcus, viridans group
E ANCA titer of 1:80