MI timeline

Question 1

4-12 hours

Answer 1

• Histo: Hypereosinophilia of myocytes
• Clinical: Elevated Troponin I

Question 2

10-14 days

Answer 2

Histo: Definite Granulation tissue w/ collagen fibers Clinical:Dressler Syndrome (Autoimmune-mediated pericarditis)

Question 3

3-7 Days

Answer 3

• Histo: Dying PMNs, Macrophages enter
• Clinical: Rupture of Free wall, ventricular septum, or papillary muscle
• Gross: Tissue is soft and appears yellow with red border due to hyperemia

Question 4

12-24 hours

Answer 4

• Histo: Coagulation Necrosis, w/ possibly PMNs
• Clinical: Serious arrhythmias *Gross: Red-blue discoloration

Question 5

1.5 to 4 hours

Answer 5

*Irreversible injury

• Histo: Wavy Fibers and Contraction Bands
• Clinical: Mural Thrombi

Question 6

2-8 Weeks

Answer 6

• Histo: Increased collagen and decreasked cellularity. Dense scar as early as 6 weeks
• Clinical: Ventricular aneurysms (Late complications)
• Gross: White, fibrous scar.

Question 7

1-3 Days

Answer 7

• Histo: Coagulation necrosis, PMNs peak at 48 hours
• Clinical: Pericardial Friction rub (due to Fibrinous pericarditis caused by PMNs)

Question 8

7-10 Days

Answer 8

• Histo: Early granulation tissue w/ proliferation of blood vessels
• Clinical: N/A