What is the definition of atherosclerosis
The accumulation of intracellular and extracellular lipid in the intima and media of large and medium sized arteries
As a consequence , the arterial walls thicken and harden
What is arteriosclerosis
The thickening of the walls of arteries and arterioles due to accumulation of lipids.
What are macroscopic features of atherosclerosis?
Fatty streak ( an early stage warning) - yellow & slightly raised. This is lipid deposits in the intima.
The simple plaque - raised yellow and white. And widely distributed.
The complicated plaque - this is where something else has happened for example thrombosis , calcification , aneurysms formation , haemorrhage in the plaque.
What are common sites of atherosclerosis?
Aorta - especially abdominal
Coronary arteries
Carotid arteries
Cerebral arteries
Leg arteries
What are microscopic features of atherosclerosis?
- Early stages : foam cells accumulation, extracellular lipid , proliferation of smooth muscle.
- Later changes : fibrosis , necrosis , cholesterol clefts because the cholesterol crystallises , a decrease or increase in inflammatory cells
More later changes : disruption of the internal elastic lamina , damage extends into the media , in growth of blood vessels , plaque rupturing / fissuring.
What are clinical effects of atherosclerosis?
Ischaemic heart disease Sudden death MI angina pectoris Arrythmia Cardiac failure
CEREBRAL ISHCAEMIA
- cerebral infaraction ( stroke)
- multi infaract dementia
INTESTINAL INFARCTION
Peripheral vascular disease
- leriche syndrome ( pain in the buttocks during exercise )
- ischaemic rest pain ( get pain in their legs even when they are at rest)
- worst case : gangrene
What factors increase the risk of atherosclerosis?
- Males are more at risk than females presumed hormonal basis
- Age - slowly progressive through adult life
- Cigarette smoking is a MAJOR risk factor
- Excess alcohol
- Diabetes mellitus
- Infection which can contribute to this
- Hyperlipidaemia : high plasma LDL contributes. High HDL levels is protective
- Oral contraceptives ( but not so much now due to les soestrogen )
- Those who. Are extremely stressed / personality type
- STRONG genetic predisposition
Why is atherosclerosis unpredictable sometimes ?
Because there could be genetic variations is Apo E which are associated with changes in LDL levels.
Thus , you can do everything you can to prevent development of atherosclerosis but still get it due to genetic predisposition
Symptoms with hyperlipidaemia
Xanthelasma - yellow deposits of cholesterol deposits usually found on the eyelids of the skin.
Corneal Arcus ( fat deposits in the outer part of the cornea )
Tendon xanthoma ( nodules found and palpules found one the tendons of the hands )
How to prevent developing atherosclerosis?
Don’t smoke
Reduce fat intake
Treat hypertension
Don’t drink too much alcohol
Regular exercise / weight control
How to intervene with atherosclerosis?
- tell patients to stop smoking
- tell patients to modify diet
- treat patients hypertension
- treat diabetes
- lipid lowering drugs
What are the cells involved in atherosclerosis?
- Endothelial cells: key role in haemostasis , altered permeability to lipoproteins , stimulation and proliferation of smooth muscle cells.
- Platlets : key role In haemostaiss , stimulates proliferation and migration of smooth muscle cells.
- Smooth muscle cells : take up LDL and other lipid to become foam cells .
- Macrophages : oxidise LDL to become foam cells.
- Lymphocytes :
- Neutrophils : secrete proteasses leading to continued local damage and inflammation
