A 30-year-old intravenous drug user presents with fever, multiple septic pulmonary emboli, and a new tricuspid regurgitation murmur. Blood cultures are positive for Pseudomonas aeruginosa. Which feature distinguishes this from left-sided infective endocarditis?
- A Vegetations are small and firmly attached
- B Embolic phenomena affect the pulmonary circulation ✓
- C Septic emboli cause systemic abscesses
- D The infection involves the mitral valve
Correct answer: B. Embolic phenomena affect the pulmonary circulation
Explanation
Right-sided endocarditis (typically tricuspid valve in IV drug users) causes septic emboli to the pulmonary circulation, producing pulmonary infarcts, abscesses, and pneumonia. Left-sided endocarditis causes systemic emboli to brain, spleen, and kidneys. S. aureus is the most common organism in right-sided IE, though Pseudomonas is also seen. Vegetations in right-sided IE are often larger and more destructive. Robbins 10th ed, Chapter 12.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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