Vascular Heart Disease

Question 1

Describe the intimal response to vascular injury

Answer 1

Intimal thickening

1. recruitment of smooth muscle cells to the intima (smooth muscle cells are normally only found in the media)
2. smooth muscle cells mitosis
3. elaboration of extracellular matrix

the thicker intima may make it more difficult for O2 and nutrients to diffuse therefore it is more prone to ischemic injury

Question 2

Arteriosclerosis

Answer 2

Hardening of the arteries” (arterial wall thickening and loss of elasticity)

Question 3

3 types of arteriosclerosis

Answer 3

Atherosclerosis
Monckeberg’s medial calcific sclerosis
Arteriosclerosis - hypertension induced

Question 4

Atherosclerosis modifiable risk factors

Answer 4

Hyperlipidemia
Hypertension
Cigarette smoking
Diabetes mellitus
“Inflammation” (increased C peptide)

Question 5

Atherosclerosis non-modifiable risk factors

Answer 5

Genetic abnormalities
Family history
Increasing age
Male gender

Question 6

“Response to injury” hypothesis:

Answer 6

Atherosclerosis is a chronic inflammatory response of the arterial wall to endothelial injury.

Lesion progression involves interaction of lipoproteins, monocyte-derived macrophages, T lymphocytes and the cellular constituents

Question 7

Atheroma morphology

Answer 7

forms inbetween the subendothelium and internal elastic lamina (intima process)
eccentric

fibrous cap
necrotic center

Question 8

what are the components of the fibrous cap of an atheroma

Answer 8

smooth muscle cells, macrophages, foam cells, lymphocytes, collagen, elastin, proteoglycans, neovascularization

Question 9

what are the components of the center of an atheroma

Answer 9

cell debris, cholesterol crystals, foam cells, calcium

Question 10

how is the media affected by an atheroma

Answer 10

the media begins to shrink and nearly dissapear in some areas due to lack of nutrients (cannot diffuse)

this thinning makes the media very weak, less elastic, and more vulnerable to becoming an aneurysm

Question 11

what are possible faits of a plaque

Answer 11

Rupture/ulceration/erosion (rupture of a cap leads to thrombus formation)
Emboli
 Hemorrhage
Weakening of media – aneurysm formation
Calcification, growth, lumen occlusion
Thrombosis

Question 12

what happens when the fibrous cap ruptures

Answer 12

platelets become exposed to the necrotic debris and basement membrane causing activation and formation of a thrombus- which further occludes the vessel and may lead to infarct and necrosis of the down stream organ

Question 13

what do cholesterol deposits look like histologically

Answer 13

they fall out of the samples and look like open (white) spaces

Question 14

Atherosclerosis- Complications

Answer 14

myocardial ischemia- angina, infarcts, sudden death

cerebral ischemia- stroke, TIA

Peripheral vascular Dz- claudication, gangrene

aneurysms- rupture

Question 15

Monckeberg’s Medial 
Calcific Sclerosis

Answer 15

Calcifium deposits
In the MEDIA
Medium sized muscular arteries
NONobstructive

Question 16

what are the 2 types of Hypertension Induced Arteriosclerosis

Answer 16

Hyaline arteriolosclerosis

Hyperplastic arteriolosclerosis

Question 17

Hyaline arteriolosclerosis

Answer 17

Arterioles

Hemodynamic stress- due to long term hypertension which causes fenestrations and plasma proteins are able to leak into wall of the vessel

Plasma protein leakage
Homogeneous pink hyaline thickening (histologically)
Lumenal narrowing

Question 18

Hyperplastic arteriolosclerosis

Answer 18

• Severe acute blood pressure elevation (200s)
• Onion skin concentric thickening
• Smooth muscle cells with thickened, reduplicated membranes
• Progressive lumenal narrowing

Question 19

what is an aneurysm

Answer 19

Localized abnormal dilatation of a blood vessel

Question 20

what is a false aneurysm

Answer 20

looks like the wall is pouching out but there was an injury to the wall of the blood vessel and now blood from the lumen is getting caught by the extravascular / external part of the blood vessel

Question 21

what leads to aneurysms

Answer 21

Poor intrinsic quality of vascular wall connective tissue
• Marfan Syndrome (defective synthesis fibrillin; loss of elastic tissue)
• Ehlers Danlos (defective type III collagen)

Weakened vascular wall through loss of smooth muscle cells or inappropriate synthesis of extracellular matrix
• Ischemia (Atherosclerosis,HTN, syphillis)
• Histology - Cystic medial degeneration

Altered balance of collagen degradation and synthesis
• Local inflammatory infiltrates
• Destructive proteolytic enzymes (Matrix metalloproteinases)

Question 22

Cystic Medial Degeneration

Answer 22

*elastin fragmentation
loss of smooth muscle cells
leading to areas resembling “cystic” spaces
weakens the blood vessel

the media normally has a very regular pattern of elastin with smooth muscle in between.

Question 23

causes of aneurysms

Answer 23

Atherosclerosis
HTN
Congenital defects
Inflammation
Infections
Vasculitis
Trauma

Question 24

Abdominal Aortic Aneurysm etiology/pathogenesis

Answer 24

• End result of a multifactorial process leading to the destruction of aortic wall connective tissue
• Matrix metalloproteinasis play a key role

Question 25

affects of atherosclerosos in AAA

Answer 25

Compresses media
Compromises nutrient and waste diffusion from vascular lumen into arterial wall
Media undergoes degeneration and necrosis
Arterial wall weakness and thinning

Question 26

pts at higher risk for AAA

Answer 26

men, who smoke, over 50 y/o

Question 27

Complications of an AAA

Answer 27

Compression/Obstruction/Embolism

Rupture

Question 28

when should you screen for an AAA

Answer 28

screen every man who has ever smoked at least once in their life

Question 29

syphilis’ affect on the aorta

Answer 29

in tertiary syphilis - lots of chronic inflammatory cells and cytokines secreted. Vaso vasorum is injured and the wall is weakened

intima becomes wrinkly like tree bark
can lead to aortic regurgitation

Question 30

Aortic Dissection

Answer 30

Blood splays apart laminar planes of the media to form a blood filled channel within the aortic wall

the intima tears and blood can enter the wall (not limited to luminal blood flow)

Question 31

causes of aortic dissections

Answer 31

HTN
Pressure related mechanical or ischemic injury
Medial hypertrophy of vasovasorum
Degenerative changes of media, loss of smooth muscle cells

Connective tissue disorders
Abnormal vascular extracellular matrix

Bicuspid aortic valves

Question 32

type A dissections

Answer 32

involve the ascending/proximal aorta (may or may not involve the descending aorta also)

Question 33

type B dissections

Answer 33

do not involve the proximal aorta

Question 34

how does an aortic dissection present

Answer 34

Sudden onset ripping chest pain radiating to back

stabbing feeling and sometimes can be felt ripping downward

Question 35

treatment of an aortic dissection

Answer 35

Medical tx – Blood pressure control (can decrease propagation)

Surgical tx (type A need to be repaired immediately but type B may or may not need surgery)