Microscopic examination of a myocardial infarction at 60 hours after occlusion of the coronary artery will show

Question

A. no microscopic changes by light microscopy
B. necrosis of myocardial cells but no inflammatory cells
C. necrosis of myocardial cells and copious infiltrates of neutrophils
D. dense infiltrates of macrophages
E. granulation tissue replacing the dead cardiac myocytes

Answer 1

C
Twenty-four to 72 hours (1 to 3 days) after the onset of the infarction, the necrotic myocardium is typically infiltrated with neutrophils. Macrophages replace the neutrophils as the primary scavengers toward the end of the first week, and thereafter granulation tissue grows into the infarcted area.