MI Healing and Complications

Question 1

What can be seen immediately after a MI

Answer 1

Nothing,earliest changes can be seen at 4 hours

Question 2

What can be observed 12 hours after MI

Answer 2

• More Eosiniphillic
• Cell strucure remains
• Nucleus is absent
• Small amount of oedema

Question 3

What can be observed 2-3 days after MI

Answer 3

• Acute inflammation where neutrophils invade the ECM
• Myocytes begin to fragment
• Macrophages begin to invade
• over the next 10 days neutrophils will remove the debris while granulation tissue beings to form

Question 4

What can be observed 14 days after MI

Answer 4

• Entirely composed of granulation tissue

Question 5

What can be observed 2 months after MI

Answer 5

• The granulation tissue becomes more fibrous and less vascular leading to a highly collagenous and relatively acellular scar by around 2 months

Question 6

Acute complications of MI

Answer 6

• Ventricullar Fibrillation, Sudden Death, Tachycardia, Acute cardiac failure, heart block, aneurysm in LV wall leading to thrombus generation, acute pulmonary congestion

Question 7

Sub acute Complications of MI

Answer 7

Rupture of LV wall or septum or puppilae muscles, inflammation leading to pericarditis

Question 8

Chronic complications of MI

Answer 8

Chronic heart Failure

Question 9

Biomarkers of MI

Answer 9

Troponin which peaks 2-3 days after MI and Creatine Kinase which peaks at around 16-24 hours after MI

Question 10

Macroscopic Changes

Answer 10

Red - initial small amount of heamorrhage which outlines site
Tan Yellow - 1-3 days after infarct
Pale - from granulation tissue and scarring

Question 11

What are percentages of CA occlusion in MI

Answer 11

LAD 40-50%
RCA 30-40%
LCA 15-20%