Pathophysiology of atheroma

Question 1

Describe the process of atherogenesis and understand how atheromatous plaques form

Answer 1

Plaques narrow lumen leading to ischaemia, myocardial ischaemia can occur due to angina and is complicated by thrombosis

Question 2

Know the components of atheromatous plaques

Answer 2

Central lipid core with fibrous tissue can covered by arterial endothelium. collagen produced by smooth muscle provides structural strength. Inflammatory cells reside in fibrous cap recruited from arterial endothelium

Question 3

Understand the role of lipids in the aetiology of atheroma.

Question 4

Know the signs of major hyperlipidaemia.

Answer 4

Biochemical evidence- LDL, HDL, total cholesterol, triglycerides
Pale ring around iris of eye, lumps on tendon, family history

Question 5

Recognise the fundamental role of atheroma in coronary, cerebrovascular and peripheral arterial disease.

Question 6

What is atherosclerosis

Answer 6

Formation of focal elevated lesions in intimal of large and medium sized arteries

Question 7

why are plaques sometimes foamy

Answer 7

due to uptake of oxidised lipoproteins via specialised membrane bound scavenger receptors

Question 7

why are plaques sometimes foamy

Answer 7

due to uptake of oxidised lipoproteins via specialised membrane bound scavenger receptors

Question 8

describe a complication atheroma

Answer 8

normal features plus haemorrhage leading to thrombosis

Question 9

Risk factors of atheroma

Answer 9

smoking, hypertension, diabetes mellitus, male, elderly,

Question 10

Describe development of atheromatous plaques

Answer 10

1. Injury to endothelial lining of artery
2. chronic inflammation and healing repose of vascular wall to agent causing injury

Question 11

long step process of development

Answer 11

Endothelial injury and dysfunction
Accumulation of lipoproteins (LDL) in vessel wall
Monocyte adhesion to endothelium → migration into intima and transformation to foamy macrophages
Platelet adhesion
Factor release from activated platelets, macrophages → smooth muscle cell recruitment
Smooth muscle cell proliferation, extracellular matrix production and T-cell recruitment
Lipid accumulation (extracellular and in foamy macrophages)

Question 12

causes of endothelial injury and what happens

Answer 12

haemodynamic disturbance (turbulent flow)
hypercholesteroaemia

enhanced expression of cell adhesion molecules
High permeability for LDL
increased thrombogenicity

Question 13

prevention of atherosclerosis

Answer 13

stop smoking, control blood pressure, weight loss, regular exercise, dietary modifications
cholestrla lowering drugs

Question 14

describe vulnerable atheromatous plaques

Answer 14

increased inflammatory activity leads to degradation, wearing of plaque and increased risk of plaque rupture