Atherosclerosis

Question 1

Mildest form

Answer 1

Fatty streak: slightly raised fibrotic plaque

Seen in younger patients

Question 2

Atheroma parts

Answer 2

Progressed from Fatty streak
Core: necrotic, cell debris, cholesterol crystals, foam cells & calcium
Fibrous Cap: Smooth muscle, macrophages, collagen, elastin

Question 3

Atheroma complications

Answer 3

1. Lipids released from dead cells attract Ca++ salts
   Vessel hardens due to calcification
2. HTN: narrow vessel, cannot adapt
3. Due to increased BP downstream can embolize
4. Aneurysm: dilation of inelastic aorta

Question 4

Aneurysm types

Answer 4

1. Saccular: ascending aorta
2. Fusiform: MC place for AAA, above iliac aa
3. Dissecting: pools in the intima–most feared
   Can lead to hemoparicardium

Question 5

Aneurysm danger

Answer 5

Rupture & death via exsanguination

Jet of blood dissects through aortic wall

Question 6

Aneurysm treatment

Answer 6

Resect & replace with Dacron or Gortex material

Question 7

Atherosclerosis steps

Answer 7

1. Endothelial damage (HTN & DM)
2. Deposition of platelets, LDL underneath endothelium
3. Platelets release growth factors that stimulate smooth
   muscle cell proliferation in tunica media
   Promotes cholesterol & LDL accumulation
4. Smooth muscle cells die & release lipids into interstitial
   space=cholesterol crystals
5. Macrophages are attracted & phagocytisize LDL/debris
   Foam cells=LDL inside Macrophage
6. Macrophages secrete cytokines, TNF–stimulate
   collagen–increase damage
7. Scarring via collagen=hardening/sclerosis

Question 8

Risk factors

Answer 8

1. Age
2. Male sex
3. Heredity
4. Lipid metabolism
5. HTN
6. Obesity
7. DM
8. Cigarette smoking
9. Stress

Question 9

Age

Answer 9

Disease of older age

Question 10

Sex

Answer 10

Male greater than Female before menopause (Estrogen increases HDL & protects)
Estrogen therapy after menopause is protective

Question 11

Heredity

Answer 11

Can be balanced by lifestyle

Familial hypercholesterolemia: LDL receptor defect, LDL can’t go into liver. Atherosclerosis at a young age

Question 12

Lipid metabolism

Answer 12

Increased LDL & TG directly correlate with extent & severity of atherosclerosis
>260 increases risk 5X than <200

Question 13

HTN

Answer 13

1. Damage platelets–aggregation & biogenic release
2. Make cells ischemic
3. Increase cytokines
4. Increase pressure compresses intimal cells

Question 14

Obesity

Answer 14

Causes secondary hyperlipidemia
Tissue fat is in equilibrium with circulating fat
Earlier age for atherosclerosis

Question 15

DM

Answer 15

1. Hypergycemia changes basement membrane metabolism & damages small vessels
2. Diabetic microangiopathy: glomular renal capillaries
   Also affects larger arteries

Question 16

Cigarette smoking

Answer 16

Due to nicotines, tar, etc

Not fully understood

Question 17

Stress

Answer 17

Constant stress may accelerate or aggravate

Question 18

Aortic atherosclerosis epidemiology

Answer 18

Men, 50 & older most have it