Flashcards in Atheroma Deck (11):
The accumulation of intracellular and extracellular lipid in the tunica intima and media of large and medium sized arteries
Thickening and hardening of arterial walls as a consequence of atheroma
What is the difference between atherosclerosis and arteriosclerosis?
Arteriosclerosis is thickening and hardening of arterial walls as a result of hypertension and/or diabetes, not atheroma
What are the macroscopic appearances of atheromas?
- Fatty streak (yellow, raised with a regular outline)
- Simple plaque (yellow/white, raised with an irregular outline, can enlarge and coalesce)
- Complicated plaque (calcification of plaque with possible haemorrhage and necrosis, increases risk of thrombosis and aneurysm formation)
What are the microscopic appearances of atheromas?
- (early) Accumulation of foam cells and proliferation of smooth muscle cells
- (later) Distribution of internal elastic lamellae, cholesterol clefts, inflammatory response, fibrosis, necrosis, plaque fissuring
What are the clinical effects of atheroma?
- Ischaemic heart disease (narrowing of coronary arteries)
- Cerebral ischaemia (narrowing of carotid arteries, infarct may result in transient ischaemic attack/stroke)
- Mesenteric ischaemia (malabsorption, infarct may result in black bowel)
- Peripheral vascular disease (intermittent claudication, buttock claudication, ischaemic rest pain)
Describe the unifying hypothesis of the formation of atheroma
- Chronic endothelial injury due to oxidised LDL, smoking or hypertension
- Endothelial injury stimulates platelet adhesion and release of PDGF which attracts macrophages and smooth muscle cells (from TM)
- SMC proliferation and insudation of lipid lead to accumulation of foam cells
- Migration of foam cells into intima (release cytokines which recruit further cells)
What are the main factors that relate to the PATHOGENESIS of atheroma? (7)
- Age and gender (males more prone, females protected pre-menopause but catch up post menopause)
- Infection (cytomegalovirus, h.pylori, chlamydia pneumoniae)
- Other factors e.g stress, genetic predisposition, obesity, ethnicity
How can you prevent atherosclerosis?
- Stop smoking
- Decrease fat intake
- Treat hypertension and/or diabetes
- Reduce alcohol consumption
- Regular exercise and control of weight
What are the clinical presentations of hyperlipidaemia?
- Tendon xanthoma
- Corneal arcus