General Pathology USMLE Step 1 Practice Question
A 61-year-old man develops crushing substernal chest pain while shoveling snow and arrives 20 minutes after symptom onset. Vital signs: BP 158/92 mmHg, HR 102 bpm, RR 18, temp 37.2°C, SpO2 98%. Troponin I is normal. Coronary angiography reveals acute thrombotic left anterior descending occlusion; reperfusion is achieved within 30 minutes. Electrocardiography shows ST elevation without pathologic Q waves. Before irreversible myocardial injury develops, which of the following represents the earliest morphologic manifestation in ischemic myocardial cells?
Answer choices
- ALysosomal rupture with autolysis
- BCalcification of mitochondria
- CNuclear fragmentation into apoptotic bodies
- DComplete dissolution of the plasma membrane
- ECellular swelling from failure of ion pumpsCorrect answer
- FAggregation of chromatin at the nuclear periphery (pyknosis)
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