Cardiovascular system and disease II

Question 1

What is Atherosclerosis?

Answer 1

• “hardening of the arteries”
• Is a generic term for thickening and loss of elasticity of arterial walls

Question 2

What is Atherosclerosis characterised by

Answer 2

• Characterised by intimal lesions which protrude into an obstruct vascular lumens

Question 3

Where does Atherosclerotic develop?

Answer 3

• Atherosclerotic plaques develop primarily in elastic arteries (e.g. aorta, carotid) and large and medium sized muscular arteries (e.g. coronary arteries)

Question 4

What is Atherosclerosis associated with

Answer 4

• Associated with increased LDL-cholesterol and reduced HDL-cholesterol

Question 5

What are the causes of Atherosclerosis

Answer 5

• Causes are still unclear

Question 6

What are the NON MODIFIABLE risk factors for Atherosclerosis

Answer 6

• Age
• Gender M>F
• Positive family history
• Genetic abnormality (eg ACE gene)

Question 7

What are the MODIFIABLE risk factors for Atherosclerosis

Answer 7

• Hyperlipidemia
• Hypertension
• Smoking
• Diabetes
• Obesity
• Physical inactivity

Question 8

What is Atherosclerotic plaques

Answer 8

build up of fats, cholesterol and other substances in and on the artery walls

Question 9

How does plaques slow blood flow

Answer 9

• The plaques protrude into the vessel lumens and

Question 10

What does plaque consists of

Answer 10

• The plaque consists of a raised lesion with a soft yellow, grumous core of lipid (mainly cholesterol and cholesterol esters) covered by a white fibrous cap

Question 11

What are the structure of atherosclerotic plaques

Answer 11

• A superficial FIBROUS CAP - SM cells, relatively dense collagen
• Beneath and to the side of the cap (“shoulder”) - a more cellular area containing macrophages, T cells, SM cells
• NECROTIC CORE (deep to the fibrous cap, containing lipid, debris from dead cells, foam cells, fibrin, variably organised thrombus, and other plasma proteins)
• The CHOLESTEROL, frequently present as crystalline aggregates or “clefts”
• NEOVASCULARISATION at the periphery of the lesions

Question 12

What are the 3 principal components of Atherosclerosis

Answer 12

• CELLS: SMCs, macrophages and other leukocytes
• EXTRACELLULAR MATRICES: collagen, elastin, proteoglycans
• INTRACELLULAR AND EXTRACELLULAR LIPID

Question 13

What are the morphology of the lesions of Atherosclerosis

Answer 13

• Earliest aortic atherosclerosis: fatty streaks:
  
  • lipid-filled foamy macrophages
  • begin as multiple minute flat yellow spots
• Advanced complicated atherosclerosis in abdominal aorta
  
  • many of the lesions have ruptured
  • become thrombosed

Question 14

Explain Endothelial injury as a key pathological event

Answer 14

• Endothelial injury will do two things:
• increases vascular permeability due to damage endothelium
• any damaged endothelium will express adhesion proteins, in normal conditions they will not be expressed

Question 15

Explain the key pathogenic events

Answer 15

• Endothelial injury: increase vascular permeability, leukocyte adhesion, and thrombosis
• Accumulation of lipoproteins: (mainly LDL) in the vessel wall
• Monocyte adhesion to the endothelium, followed by migration into the intima and transformation into macrophages and foam cells
• ## Platelet adhesion

Question 16

describe the consequences of Rupture, ulceration or erosion of the intimal surface

Answer 16

• rupture, ulceration or erosion of the intimal surface -> highly thrombogenic substances -> thrombosis

Question 17

Describe the consequences of Haemorrhage into a plaque

Answer 17

• Haemorrhage/bleeding into a plaque. Rupture of the fibrous cap -> intra-plaque haemorrhage -> plaque rupture

Question 18

Describe the consequences of Atheroembolism

Answer 18

• Plaque rupture -> atherosclerotic debris into bloodstream -> microemboli

Question 19

Describe the consequences of Aneurysm formation

Answer 19

• Atherosclerosis-induced pressure, ischemic atrophy, loss of elastic tissue -> weakness -> aneurysmal dilation and potential rupture

Question 20

What does the clinical outcome of atherosclerotic depend on

Answer 20

• Size of the involved vessels
• Relative stability of the plaque itself
• Degree of degeneration (underlying arterial wall)

Question 21

What are the major consequences of atherosclerotic diseases

Answer 21

• Myocardial infraction (heart attack)
• Cerebral infraction (stroke)
• Aortic aneurysms
• Peripheral vascular disease (gangrene of the legs)

Question 22

What is Ischemic heart disease and what is its cause

Answer 22

• Leading cause of death WORLDWIDE for both men and women
• the cause of myocardial ischemia is reduced blood flow due to obstructive atherosclerotic lesions in the coronary arteries

Question 23

what are the clinical manifestations of ischemic heart disease

Answer 23

• Angina pectoris
• Myocardial infraction , the most important form of IHD
• Heart failure
• Sudden cardiac death

Question 24

What is chest pain also known as

Answer 24

• Angina pectoris

Question 25

What is chest pain/angina pectoris characterised by

Answer 25

• paroxysmal and usually recurrent attacks
• substernal or precordial chest discomfort
• variously described as constricting, squeezing, choking, knifelike
• caused by transient (15 seconds to 15 minutes) myocardial ischemia

Question 26

What are the 3 overlapping patterns of angina pectoris

Answer 26

1) Stable or typical angina
2) Variant (Prinzmetal, vasospastic) angina
3) Unstable (crescendo) angina

Question 27

What is heart attack also known as

Answer 27

• Myocardial infraction

Question 28

What is Myocardial infraction

Answer 28

• also known as heart attack, is the death of cardiac muscle due to prolonged severe ischemia

Question 29

What is the pathogenesis of Myocardial infraction

Answer 29

• Pathogenesis: Coronary arterial occlusion

Question 30

What is the causes of coronary arterial occlusion

Answer 30

• Coronary atherosclerosis (90%)
• Vasospasm with or without coronary atherosclerosis
• Emboli from the left atrium in association with atrial fibrillation
• Others