L11- Infarction and embolism

Question 1

What is an infarct?

Answer 1

An area of ischaemic necrosis within a tissue or organ produced by occlusion of either its arterial supply or venous drainage

Question 2

What can cause an infarct?

Answer 2

1. Thrombosis e.g MI of coronary arteries

2. Embolism from lung, kidney or spleen

Question 3

What are the two types of MI?

Answer 3

Subendocardial infarct- ischaemic necrosis of inner 1/3 or at most 1/2 of the ventricular wall. No plaque rupture or thrombosis but coronary atherosclerosis present and reduction in flow

Question 4

What is a transmural infarct?

Answer 4

Transmural infarct- ischaemic necrosis of full or nearly full thickness of ventricular wall in the distribution of coronary artery, usually associated with atherosclerosis plaque rupture and thrombosis

Question 5

What is coagulative necrosis?

Answer 5

Cells have died but the proteins within them have been coagulated and preserved

Question 6

What are the morphological complications following MI?

Answer 6

Early- arrythmias, heart failure, pericarditis, papillary muscle dysfunction

Late- ventricular aneurysm, ischaemia, re-infarction

Question 7

What is an embolism?

Answer 7

The transfer of abnormal material by the bloodstream and its impactation in a vessel

Question 8

What are the types of emboli?

Answer 8

Can be solid, liquid or gas
• fragments of a thrombus
• septic emboli
• tumour fragments
• fat globules
• air emboli

Question 9

What is pulmonary embolism?

Answer 9

• Results from the detachment of a thrombus in a systemic vein (usually deep venous plexus of leg) and travel to right side of heart
• Causing sudden blockage of pulmonary trunk or major division
• Sudden death or respiratory depression