CHD

Question 1

What is tissue ischaemia?

Answer 1

Reduced blood flow to an organ/tissue

Question 2

Tissue ischaemia leads to a lack of what?

Answer 2

• O2
• nutrients
• washout of metabolic wastes

Question 3

What determines the extent of tissue damage due to tissue ischaemia?

Answer 3

• organ

- duration

Question 4

Longer reduction of blood flow to tissues is more likely to be reversible/irreversible damage

Answer 4

irreversible

Question 5

What is myocardial ischaemia?

Answer 5

Reduced blood flow to the heart

Question 6

What is ischaemia?

Answer 6

Imbalance between myocardial O2 supply and demand

Question 7

When does exertional demand ischaemia occur?

Answer 7

During activity/stress

Question 8

Why does exertional demand ischaemia occur?

Answer 8

O2 demand increases & more ATP and nutrients required due to increased HR

Question 9

When does non-exertional supply ischaemia occur?

Answer 9

At rest

Question 10

Why does non-exertional supply ischaemia occur?

Answer 10

When there is insufficient O2

Question 11

Describe the 2 possible conditions of the coronary arteries during non-exertional supply ischaemia?

Answer 11

• Plaque closes the artery

- Plaque ruptures -> clot forms -> artery closes -> heart attack

Question 12

Define coronary heart disease

Answer 12

Reduced blood flow to heart due to obstructive/constrictive disease of coronary arteries

Question 13

Describe the disease process of CHD

Answer 13

-> coronary artery obstruction/constriction
-> reduced blood flow to heart
-> O2 & nutrient deprivation, accumulation of toxic wastes
Leading to:
Metabolic dysfunction
Contractile dysfunction
Electrical instability
Myocardial cell death

Question 14

What are the clinical manifestations of CHD?

Answer 14

Angina (stable/variant/microvascular)
ACS (unstable angina/MI NSTEMI/STEMI)
Sudden cardiac death

Question 15

List the 4 pathological diseases of CHD

Answer 15

Atherosclerosis
Coronary thrombosis
Coronary artery spasm
Coronary microvascular dysfunction

Question 16

Define atherosclerosis

Answer 16

Degenerative, progressive arterial disease characterised by asymmetric deposition of lipids and fibrous tissue on artery walls

Question 17

What is the most common cause of CHD?

Answer 17

Atherosclerosis

Question 18

What type of process is atherosclerosis?

Answer 18

Inflammatory

Question 19

Give 3 medical risk factors of CHD

Answer 19

Hypercholesterolaemia
Diabetes
HPT

Question 20

Give 4 modifiable risk factors of CHD

Answer 20

Diet
Obesity
Smoking
Physical Activity

Question 21

Describe the disease process of atherosclerosis whereby an atheroma/fibrous plaque is formed

Answer 21

• > LDL deposition in sub-endothelial space
• > LDL oxidation & monocyte recruitment
• > Uptake of oxidised LDL & macrophage differentiation
• > Foam cell formation
• > SMC migration, proliferation & de-differentiation

Question 22

List the 3 possible consequences of atherosclerosis

Answer 22

Stable angina - partial coronary occlusion
Coronary artery spasm - endothelial/vascular dysfunction
Coronary thrombosis - ulceration/rupture

Question 23

Define Coronary thrombosis

Answer 23

Unwanted formation of a haemostatic plug within coronary arteries

Question 24

Describe the disease process of coronary thrombosis

Answer 24

• > Rupture/ulceration of atherosclerotic plaque
• > Contact of blood elements with collagen & TF
• > Platelet adhesion & activation leads to platelet aggregation
• > Activation of the coagulation cascade
• > Fibrin formation & deposition
• > Clot

Question 25

List the possible consequences of coronary thrombosis

Answer 25

ACS - complete & permanent OR intermittent occlusion of artery Thromboembolism in distal artery

Question 26

Define coronary artery spasm

Answer 26

Transient & spontaneous coronary vasoconstriction

Question 27

Coronary artery spasm is the underlying cause of which type of angina?

Answer 27

variant angina

Question 28

Describe the 3 disease mechanisms of coronary artery spasm

Answer 28

- local endothelial injury -> increased reactivity to vasoconstrictors - abnormal release of vasoconstrictors & constrictors - smooth muscle cell hyper-contraction

Question 29

Describe the impact on coronary function due to coronary artery spasm

Answer 29

Intermittent OR complete occlusion of coronary artery

Question 30

Define coronary microvascular dysfunction

Answer 30

Inner wall damage of small coronary blood vessels of heart leading to microvascular spasms, decreased blood flow to the heart muscle & decreased coronary flow reserve

Question 31

Coronary microvascular dysfunction is the underlying cause of which type of angina?

Answer 31

microvascular angina

Question 32

State the result of structural & functional damage due to coronary microvascular dysfunction

Answer 32

structural -> microvascular remodelling | functional -> endothelial dysfunction

Question 33

State the 3 disease mechanisms of coronary microvascular dysfunction

Answer 33

microvascular remodelling endothelial dysfunction functional abnormalities

Question 34

Describe microvascular remodelling

Answer 34

Luminal narrowing of intramural arterioles & capillaries -> microvascular obstruction

Question 35

Describe endothelial dysfunction

Answer 35

Impaired vasodilator response & reduced coronary blood during exercise/stress

Question 36

Describe the effect of functional abnormalities of smooth muscle cells

Answer 36

Regulates arterial tone

Question 37

Describe the impact on coronary function due to coronary microvascular dysfunction

Answer 37

Decreased coronary flow reserve Increased risk of myocardial ischaemia INOCA/MINOCA