Histology of myocardium distal to a successfully reopened coronary artery shows hypercontracted sarcomeres with wavy transverse bands of densely eosinophilic material crossing myocytes. This finding indicates:
- A Contraction band necrosis from reperfusion injury ✓
- B Coagulative necrosis of irreversible ischemia
- C Myofiber disarray of hypertrophic cardiomyopathy
- D Early granulation tissue of healing infarction
Correct answer: A. Contraction band necrosis from reperfusion injury
Explanation
Reperfusion restores calcium influx into lethally injured myocytes, producing hypercontraction of sarcomeres with prominent transverse contraction bands on histology. It is the microscopic hallmark of reperfused infarcts, including those after thrombolysis or angioplasty. Coagulative necrosis shows anuclear, eosinophilic fibers without contraction bands, myofiber disarray is a genetic feature of hypertrophic cardiomyopathy unrelated to ischemia, and granulation tissue appears only after about a week.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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