Atherosclerosis and MI Flashcards
(48 cards)
What is cardiogenic shock?
Loss of perfusion due to malfunction of the heart
What is ischaemic heart disease?
All heart diseases resulting from reduced O2 supply to heart muscle
List three forms of acute coronary syndrome (ACS)
- Angina
- Acute coronary occlusion
- Myocardial infarction
Describe how an atheroma is formed
There is a tear in an artery wall; fatty material is deposited in the wall and the narrowed artery becomes blocked by a blood clot
What are statins?
Drugs that reduce/prevent cholesterol build-up in vessels
What two things may occur when fatty acids are present via diet/liver synthesis?
Oxidised for fuel, or converted to triglycerides and stored in adipose tissue
Free fatty acids travel through blood bound to which protein?
Albumin
Triglycerides (TAGs) and cholesterol are transported between organs in ____.
Lipoproteins
What are lipoproteins?
Lipid droplets assembled around protein particles called apo-lipoproteins
Apo-lipoproteins drive the metabolism of particles by…
Binding to receptors on cell membranes
What is the relevance of LDL to cardiovascular disease?
LDL is small enough to enter the arterial wall and deposit lipids between endothelium and smooth muscle
Macrophages in blood vessels cannot regulate cholesterol uptake and so become what kind of cells?
Foam cells
What are foam cells?
Lipid-loaded macrophages that secrete pro-inflammatory cytokines
What is the major function of HDL?
To remove cholesterol from peripheral tissues and return it to the liver to be degraded to bile acids and excreted; this is why they are associated with CVD prevention
Describe Tangier’s disease
- Rare genetic disease
- Mutation in a cholesterol transporter required to move cholesterol out of cells
- Almost complete lack of HDL
- Hypertriglyceridaemia (high TAG levels)
- Early onset atherosclerosis
Describe the development of atherosclerosis
- LDL deposits lipids between endothelium and smooth muscle
- Accumulation of LDL in sub-endothelial space triggers endothelial cells to secrete chemokines
- Chemokines induce monocyte infiltration
- Monocytes differentiate into macrophages
- Macrophages phagocytose LDL
- Sustained LDL uptake induces foam cell formation
- Foam cells cannot leave the lesion, and recruit other inflammatory cells
Give three examples of how atherosclerotic lesions can become unstable
- Necrosis/apoptosis of foam cells
- Increased inflammation
- Breakdown of the fibrous cap
What can trigger the core necrosis in an atherosclerotic lesion?
Necrosis of the foam cells can occur as a consequence of:
- Growth factor deprivation
- Hypoxia
- Toxic cytokines
- ER stress due to excess cholesterol accumulation in the ER membrane
Activated mast cells promote which conversion process?
Macrophages into foam cells
How do mast cells become activated and what do they release to trigger conversion?
Mast cells bind to molecules and become ‘activated’, and release secretory granules which contain enzymes (proteases), heparin and histamine
What is the effect of mast cells in relation to macrophage function?
Mast cells make LDL more accessible to macrophages, promoting foam cell conversion, while removing HDL from the region
How do ACE inhibitors contribute to hypertension rx?
Inhibit activation of angiotensin, an enzyme that increases BP
How do diuretics contribute to hypertension rx?
Reduce blood volume, therefore BP
How do calcium channel blockers contribute to hypertension rx?
Reduce muscle tone in artery walls
