Pathophysiology of Atheroma

Question 1

What is Atheroma?

Answer 1

Formation of focal elevated lesions (plaques) in intima of large and medium sized arteries

Question 2

What does atheroma in coronary arteries cause?

Answer 2

Ischaemia

Question 3

What is arteriosclerosis?

Answer 3

Age-related thickening, hardening and loss of elasticity in muscular arteries

Question 4

What is the earliest significant lesion in atheroma?

Answer 4

A fatty streak

Question 5

What is a fatty streak?

Answer 5

A yellow linear elevation of intimal lining comprised of masses of lipid-laden macrophages with no clinical significance

Question 6

What can a fatty streak develop into?

Answer 6

Early atheromatous plaque

Question 7

What is an early atheromatous plaque?

Answer 7

Smooth yellow patches in the intimal which is made of lipid-laden macrophages

Question 8

What does an early atheromatous plaque develop into?

Answer 8

Established plaques

Question 9

What is a fully developed atheromatous plaque?

Answer 9

Central lipid core with fibrous tissue cap, covered by arterial endothelium

Question 10

What resides inside the fibrous cap of an atheromatous plaque?

Answer 10

Inflammatory cells recruited from arterial endothelium

Question 11

What occurs in late stage plaque development?

Answer 11

Dystrophic calcification

Question 12

Where do plaques form?

Answer 12

At arterial branching points (bifurcations)

Question 13

What are the characteristics of a complicated atheroma?

Answer 13

Haemorrhage into the plaque
Plaque rupture
Thrombosis

Question 14

What is the most important risk factor of atheroma?

Answer 14

Hypercholesterolaemia

Question 15

What are the major signs of hyperlipidaemia?

Answer 15

Corneal arcus
Tendon xanthomata
Xanthelasmata
Biochemical evidence

Question 16

What are the high risk factors of atheroma?

Answer 16

Smoking 
Hypertension 
Diabetes mellitus 
Male 
Elderly 
Accelerated process of plaque formation driven by lipids

Question 17

What are the less strong risk factors of atheroma?

Answer 17

Obesity
Sedentary lifestyle
Low socio-economic status
Low birthweight

Question 18

What are the two steps involved in the formation of atheromatous plaque?

Answer 18

1. Injury to the endothelial lining of the artery
2. Chronic inflammatory and healing response of vascular wall to agent causing injury

It is the chronic exposure of the arterial wall to these processes that cause the atheromatous plaque to form

Question 19

What are the most important causes of endothelial injury in atheromatous plaque formation?

Answer 19

Haemodynamic disturbance

Hypercholesterolaemia

Question 20

How does injury to the endothelial cells cause plaque formation?

Answer 20

There is a change to the endothelial cells functionally so there is enhanced expression of cell adhesion molecules. This causes high permeability for LDL and increased thrombogenicity

Question 21

How do plaques grow?

Answer 21

The established plaques growth is initiated by small areas of endothelial loss

Question 22

What is the clinical significance of atheroma?

Answer 22

Progressive lumen narrowing due to high grade plaque stenosis
Acute atherothrombotic occlusion
Embolisation of distal arterial bed
Ruptured atheromatous abdominal aortic aneurysm

Question 23

What does an acute atherothrombotic occlusion cause?

Answer 23

Myocardial infarction
Stroke
Lower limb gangrene

Question 24

What are the preventative and therapeutic approaches to atheroma?

Answer 24

Stop smoking 
Control blood pressure 
Weight-loss 
Regular exercise  
Dietary modifications

Question 25

What are the secondary preventative methods for atherma?

Answer 25

Cholesterol lowering drugs and aspirin