A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 64-year-old male presents to the emergency room complaining of chest pain. He reports a pressure-like sensation over his sternum that radiates into his jaw. The pain came on suddenly 2 hours ago and has been constant since then. His past medical history is notable for a stable abdominal aortic aneurysm, hypertension, diabetes, and hyperlipidemia. He takes aspirin, enalapril, spironolactone, atorvastatin, canagliflozin, and metformin. His temperature is 99.1°F (37.3°C), blood pressure is 155/85 mmHg, pulse is 115/min, and respirations are 22/min. On exam, he is diaphoretic and in moderate distress. He is admitted for further management and does well after initial stabilization. He is seen two days later by the admitting team. This patient is at increased risk for a complication that is characterized by which of the following?
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A
Friction rubCorrect. peri-infarction (early post-MI) pericarditis develops days 1-4 after transmural MI as fibrinous inflammation overlying the infarct, producing a pericardial friction rub.
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B
Intra-cardiac shuntIncorrect. Intra-cardiac shunt would result from ventricular septal rupture, a mechanical complication occurring 3-7 days post-MI; it presents with a new harsh holosystolic murmur and acute heart failure, not friction rub.
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C
Mitral insufficiencyIncorrect. Mitral insufficiency from papillary muscle rupture causes a new holosystolic murmur radiating to the axilla and acute pulmonary edema, not a friction rub.
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D
Ventricular fibrillationIncorrect. Ventricular fibrillation is most common in the first 24-48 hours of acute MI and would not typically arise on day 2 in a stabilized patient; it's also not 'characterized by' a specific exam finding.
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E
Left ventricular free wall ruptureIncorrect. Free wall rupture occurs 5-14 days post-MI and produces sudden tamponade, hypotension, and electromechanical dissociation — a catastrophic event, not the indolent friction rub that characterizes peri-infarction pericarditis on day 2.
↑ Tap an answer to reveal the reasoning
Answer: A. A 64-year-old man with classic STEMI presentation (substernal pressure radiating to the jaw, diaphoresis, tachycardia) is admitted, stabilized, and then 'seen two days later' — meaning he's now post-MI day 2-3. The question asks about a complication characterized by friction rub.
In the first few days (typically days 1-4) after a transmural MI, patients can develop fibrinous pericarditis from inflammation of the epicardium overlying the infarcted myocardium. This is sometimes called peri-infarction pericarditis or early post-MI pericarditis. The hallmark physical finding is a pericardial friction rub — a scratchy, three-component rub heard best at the left sternal border. The EKG can show diffuse ST elevations and PR depressions. Treatment is high-dose aspirin (NSAIDs and steroids are generally avoided early post-MI as they may impair healing).
The other complications have different timing: ventricular fibrillation is most common in the first 24-48 hours (during acute ischemia, not 2 days later as a developing complication); papillary muscle rupture/VSD/free wall rupture occur 3-7 days post-MI (mechanical complications). Dressler syndrome (autoimmune pericarditis with effusion) occurs weeks later. Mitral insufficiency from papillary muscle rupture typically presents as new murmur and pulmonary edema, days 3-7.
**Why each option:**
**A.** Correct — peri-infarction (early post-MI) pericarditis develops days 1-4 after transmural MI as fibrinous inflammation overlying the infarct, producing a pericardial friction rub.
**B.** Intra-cardiac shunt would result from ventricular septal rupture, a mechanical complication occurring 3-7 days post-MI; it presents with a new harsh holosystolic murmur and acute heart failure, not friction rub.
**C.** Mitral insufficiency from papillary muscle rupture causes a new holosystolic murmur radiating to the axilla and acute pulmonary edema, not a friction rub.
**D.** Ventricular fibrillation is most common in the first 24-48 hours of acute MI and would not typically arise on day 2 in a stabilized patient; it's also not 'characterized by' a specific exam finding.