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?
- A)Lysosomal rupture with autolysis
- B)Calcification of mitochondria
- C)Nuclear fragmentation into apoptotic bodies
- D)Complete dissolution of the plasma membrane
- E)Cellular swelling from failure of ion pumpsGABARITO
Explicação
The earliest morphologic change in reversible ischemic injury is cellular swelling caused by ATP depletion and failure of the sodium potassium ATPase and calcium pumps. In myocardial ischemia, loss of contractile function occurs quickly, but the classic struct... Ver explicação completa e trilha adaptativa →