A 58-year-old man develops fever, pleuritic chest pain, and a pericardial friction rub 3 weeks after an acute anterior STEMI. Echocardiography shows a moderate pericardial effusion without tamponade. Which of the following is the most likely underlying mechanism of this condition?

• A Direct extension of myocardial necrosis into the pericardium
• B Autoimmune reaction against exposed myocardial antigens ✓
• C Bacterial seeding of the pericardial space from bacteremia
• D Uremic pericarditis due to acute kidney injury

Explanation

This is Dressler syndrome, an autoimmune-mediated pericarditis occurring weeks after MI due to formation of antibodies against exposed myocardial antigens. It is distinct from early post-infarction pericarditis (direct extension into pericardium, occurring days 1-3). Bacterial pericarditis and uremic pericarditis are unrelated to the post-MI timeline.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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