CHD INTRO

Question 1

what are the 4 pathogenesis of IHD/ CHD

Answer 1

1- Atherosclerosis
2- Coronary Thrombosis
3- Coronary artery spasm
4- Coronary microvascular dysfunction

Question 2

define myocardial ischaemia

Answer 2

reduced regional blood flow to the heart.

imbalance between myocardial demand and supply.

Question 3

define tissue ischaemia

Answer 3

reduced blood flow to an organ or tissue.
due to lack of O2 and nutrient supply.
and lack of washout of metabolic waste.

Question 4

what are the types of tissue ischaemia?

Answer 4

reversible and irreversible tissue dammage.

Question 5

what increases O2 demand?

Answer 5

wall stress
heart rate
contractility

Question 6

what increases O2 supply?

Answer 6

near max supply at rest

Question 7

define CHD

Answer 7

Coronary heart disease- pathological conditions characterised by a reduced or inadequate blood flow to the heart, usually due to an obstructive disease of the coronary arteries.

Question 8

is CHD curable?

Answer 8

no but it can be prevented before you get it .. exercise/ diet etc

Question 9

what is the 4 basic step disease process of CHD

Answer 9

1- Coronary artery obstruction or constriction
2- reduced regional blood flow to the heart
3- oxygen and nutrient deprivation and accumulation of toxic wastes
4- metabolic dysfunction/ contractile dysfunction/electrical instability/ myocardial cell death

Question 10

what are the clinical manifestations of CHD?

Answer 10

1- angina pectoris
2- immediate or sudden cardiac death ( do not see doctor)
3- acute coronary syndromes (acs) - see a doctor and are diagnosed- unstable angina/ acute myocardial infraction.

Question 11

define Atherosclerosis

Answer 11

a progressive, degenerative arterial disease characterised by asymmetric deposition of lipids and fibrous tissue on the inside walls of arteries.
most common cause of CHD

Question 12

What is the disease process with atherosclerosis? (short)

Answer 12

inflammatory process, begins as a fatty streak

Question 13

what is the 6 step disease process with atherosclerosis?

Answer 13

1- LDL deposition in sub-endothelial space
2-LDL oxidation and monocyte recruitment into sub- endothelial space
3- Macrophage differentiation +uptake of oxidized LDL
4- foam cell formation
5- SMC migration, proliferation & de-differentiation
6- fibrous plaque or atheroma

Question 14

what does the modified LDL stimulate?

Answer 14

stimulates the expression of MCP-1 in endothelial cells

Question 15

what does MCP-1 attract?

Answer 15

MCP-1 attracts monocytes into the subendothelial space

Question 16

where do monocytes differentiate into macrophages?

Answer 16

in the subendothelial space.

Question 17

what induces macrophages to release cytokines that stimulate adhesion molecule expression in endothelial cells?

Answer 17

modified LDL induces this

Question 18

what expresses receptors that take up modified LDL?

Answer 18

macrophages

Question 19

what expresses growth factors and proteinases?

Answer 19

macrophages and foam cells

Question 20

what is a consequence of atherosclerosis?

Answer 20

impact on coronary function: stable angina/ coronary artery spasm/ coronary thrombosis

Question 21

define coronary thrombosis

Answer 21

unwanted formation of a haemostatic plug or thrombus or blood clot within coronary arteries

Question 22

where does coronary thrombosis occur

Answer 22

usually on top of a ruptured atheroma(plaque)

Question 23

what is the 4-step disease process in coronary thrombosis

Answer 23

1-ruptured plaque
2- contact of blood elements with collagen and tissue factor
3-platelet adhesion/activation and aggregation OR activation of the coagulation cascade with fibrin formation and deposition
4- clot

Question 24

what are the consequences of coronary thrombosis?

Answer 24

1-impact on coronary function:

acs or thromboembolism in a distal artery

Question 25

define coronary artery spasm

Answer 25

a transient, spontaneous coronary vasoconstriction

Question 26

what are the disease mechanisms for coronary artery spasm

Answer 26

1- local endothelial injury= inc reactivity to vasoconstrictors
2 abnormal release of vasoconstrictors or local imbalance in release of vasodilators and constrictors
3- smooth muscle cell hypercontraction/ hyper-reactivity

Question 27

what are the consequences of coronary artery spasm?

Answer 27

impact on coronary artery function

Question 28

what does GTN do?

Answer 28

improves blood flow

Question 29

define coronary microvascular dysfunction

Answer 29

damage to the inner walls of the small coronary blood vessels of the heart, leading to microvascular spasms, decreased blood flow to the heart, muscle and reduced coronary flow reserve.

Question 30

what are the two types of damage that coronary microvascular dysfunction can do?

Answer 30

structural -microvascular remodelling

functional- endothelial dysfunction

Question 31

what are the disease mechanisms of coronary microvascular dysfunction?

Answer 31

microvascular remodeling- luminal narrowing of the intramual arterioles and capillaries- microvascualr obstruction
2- endothelial dysfunction- impared vasodilator response and reduced coronary blood during exercise or stress
3-functional abnormalities of smooth muscle cells that regulate arteriolar tone

Question 32

consequence of coronary microvascular dysfunction

Answer 32

impact on coronary flow reserve& inc risk of myocardial ischarmia= INOCA OR MINOCA