Atherosclerosis

Question 1

Definition

Answer 1

An inflammatory disease of the large and medium sized systemic arteries, characterised by the formation of lipid-rich plaques in the vessel wall

Question 2

Pathophysiology

Answer 2

Endothelial injury leads to an inflammatory and fibroproliferative reaction in the artery, culminating in atherosclerosis
– lipid plaques causing the lumen of the arteries to narrow

Endothelium may be damaged by multiple factors, smoking, hyperglycaemia and oxidised low-density lipoproteins (LDL’s)

LDL’s:
– particularly potent at driving atherosclerosis through its pro inflammatory and procoagulant affects

Stable plaques:
– very few inflammatory cells and a thick fibrous cap narrow the lumen of the artery but are less likely to cause acute complications
– not as vulnerable to erosion and come off

Unstable plaques:
– more inflammatory cells and they have a thin fibrous cap that is vulnerable to erosion, cracking or rupture.
– exposure of the highly thrombogenic lipid core to the blood causes an acute ischaemic event in the organ that artery is supplying

Stable plaques cause:
– symptoms of reversible ischaemia in the supplied organ e.g: angina pectoris, chronic lower limb ischaemia

Unstable plaques cause:
– acute ischaemic events
e.g:
—- acute coronary syndromes, stroke, acute lower limb ischaemia