Pulmonary Embolism USMLE Step 1 Practice Question
A 28-year-old woman with a 4-year history of systemic lupus erythematosus (SLE) presents to the emergency department with acute onset dyspnea and pleuritic chest pain that began this morning. She has been anticoagulated with warfarin for 18 months due to antiphospholipid antibody syndrome. Vital signs: BP 128/82 mmHg, HR 106 bpm, RR 22/min, SpO2 94% on room air. Physical examination reveals clear lung fields and no peripheral edema. Laboratory studies show INR 2.1 (therapeutic), D-dimer 0.8 μg/mL (elevated), normal troponin I, and normal creatinine. Bilateral lower extremity compression ultrasound is negative for deep vein thrombosis. CT pulmonary angiography shows no pulmonary arterial filling defects or acute infarction. Which of the following is the most likely diagnosis?
Answer choices
- AAcute myocardial infarction with normal troponin
- BAcute decompensated heart failure
- CSLE-associated myocarditis or pleuritisCorrect answer
- DCatastrophic antiphospholipid syndrome
- EWarfarin-induced skin necrosis
- FAcute bacterial pneumonia
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