3. Definition
- Athero sclerosis
Fatty paste hardening
- Definition: “thickening and hardening of large and medium
sized arteries due to fibrofatty plaques(atheromas)”
- Affects mainly the aorta, coronary arteries(heart) and cerebral
arteries(brain)
- Can cause heart attacks, stroke and other conditions
6. Modifiable risk factors
1. Hyperlipidemia: increase in serum cholesterol
➢ High levels of Low density lipoprotein(LDL) - “bad
cholesterol”
➢ High-density lipoprotein(HDL) - “good cholesterol”
1. Hypertension: increase in systolic and diastolic blood
pressure
2. Cigarette smoking: most important avoidable cause of
atherosclerosis
3. Diabetes mellitus
9. Pathogenesis- “Response to Injury” hypothesis
Exposure to risk factors
-> Formation of fatty streaks
-> lipoprotein particles accumulate inside intima and macrophages
enter into the lesion
-> macrophages ingest the lipoprotein and transform into "foam
cells"
-> macrophages release cytokines and lead to smooth muscle
proliferation
10. -> some foam cells die - formation of lipid-rich core
-> fibrous tissue forms around lipid-laden macrophage - formation
of fibrous cap
-> this fully developed plaque/atheroma can undergo calcification
-> plaque can bulge into lumen of coronary artery and narrow it
-> thrombosis can occur, leading to complete block of blood vessel
and causing acute coronary syndrome
11. Pathogenesis(short version)
Exposure to risk factors formation of fatty streak
-> lipoproteins accumulate, macrophage migration
-> streak develops into a fully-developed atheroma
-> Atheroma can undergo calcification or thrombosis(“complicated
plaque”)
-> Leading to clinical events(acute coronary syndrome, stroke, limb
ischemia)
12.
13.
14.
15. Morphological features
Gross:
- Site: lower abdominal aorta, coronary arteries, popliteal
arteries, internal carotid arteries and circle of Willis
- Appearance: yellow oval lesions
16.
17. Microscopy:
Plaque is made up of:
- Superficial fibrous cap
- Necrotic core: cholesterol cleft, foam cells
- Shoulder: peripheral area below and on the sides of the
cap
18.
19. Clinical effects
- Artery becomes narrow ischemia and atrophy
- Artery can get blocked suddenly infarction and necrosis
- Plaque can break thrombus and embolisation
- Artery wall can became weak and dilate aneurysm and rupture
20. Clinical significance
Causes a number of diseases, such as:
- Heart -> ischemic heart disease, myocardial infarction
- Brain -> chronic ischemic brain damage, stroke
- Aorta -> aneurysm formation, thrombosis and embolisation to other
organs
- Small intestine -> ischemic bowel disease, infarction
- Lower extremities -> intermittent claudication, gangrene
21.
22.
23. Prevention
Primary prevention: Targeting modifiable risk factors to prevent occurrence
of disease
Secondary prevention: after the disease process has already started
- Stop smoking - most important avoidable cause
- Maintain serum cholesterol: reduce levels of LDL, increase levels of
HDL
- Can be done via diet and drugs
- Low cholesterol diet, cholesterol-lowering medications(statins)
24. - Control blood pressure - via lifestyle(diet and exercise) and
antihypertensive medications(ACE inhibitors, beta blockers, calcium
channel blockers)
- Diabetic control(through diet/exercise/medications)
- Regular exercise (brisk walking, cycling or swimming for 20 minutes
two or three times a week) has a protective effect.
