| Time | Gross Features | Light Microscopic Findings | Electron Microscopic Findings |
| Reversible Injury |
| central yellow-tan softening necrosis |
|
| 0 - ½ hr | None | None | Relaxation of myofibrils; glycogen loss; mitochondrial swelling |
| ½ - 4 hr | None | Usually none; variable waviness of fibers at border | Sarcolemmal disruption; mitochondrial amorphous densities |
| 4 - 12 hr | Occasionally dark mottling | Beginning coagulation necrosis; edema; hemorrhage |
|
| 12 - 24 hr | Dark mottling | Ongoing coagulation |
|
| 1 - 3 days | Mottling with yellowtan infarct center | central yellow-tan softening necrosis; pyknosis of nuclei; myocytehypereosinophilia; marginal contraction band necrosis; beginning neutrophilic infiltrate Coagulation necrosis, with loss of nuclei and striations; interstitial |
|
| 3 - 7 days | Hyperemic border | infiltrate of neutrophils Beginning disintegration of dead myofibers, with dying neutrophils; early phagocytosis of dead cells by macrophages at infarct border |
|