Coronary Artery Disease USMLE Step 1 Practice Question
A 73-year-old man with chronic atrial fibrillation and a history of myocardial infarction presents with acute onset of severe left leg pain and pallor. Vital signs show HR 110 bpm (irregular), BP 138/82, RR 18, temp 37.2°C. Physical examination reveals the left foot is cool and pulseless below the knee with diminished sensation. ECG demonstrates atrial fibrillation. Doppler ultrasound shows acute arterial occlusion. He denies recent trauma. Which structure is the most likely source of the occluding embolus?
Answer choices
- AThrombus in the superior vena cava
- BVegetation on the tricuspid valve
- CAtheromatous plaque from the pulmonary artery
- DDeep venous thrombosis in the calf
- EMural thrombus in the left atriumCorrect answer
- FAortic atherosclerotic plaque shedding peripheral emboli
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