Atherosclerosis and heart disease Flashcards
What are the modifiable risk factors of heart disease?
- Smoking
- Lipids intake
- Blood pressure
- Diabetes
- Obesity
- Sedentary lifestyle.
What are the non-modifiable risk factors of heart disease?
Age, sex and genetic background
What three factors when combined increase heart disease risk exponentially?
1) Smoking
2) Hypertension
3) High cholesterol
What happens to low density lipoproteins once deposited in the subintimal space?
Binds to matrix proteoglycans and becomes oxidised by reactive oxygen species released by macrophages
What is the step of atherosclerosis?
Coronary artery at lesion-prone location (adaptive thickening of smooth muscle)
What is a type II lesion?
Macrophage transmigration into the subendothelial space, phagocytosis oxidised lipoproteins forming foam cells.
What is a type III lesion?
Preatheroma: Small pools of extracellular lipid
What is a type IV lesion?
Atheroma - core of extracellular lipid forms
What is a type V lesion?
Fibroatheroma, progressive fibrosis; thickening the fibrous cap; separating the lipid core from the lumen
What is a complicated lesion?
Fissure and haematoma and thrombus formation
How do complications arise due to plaque formation?
Due to extensive growth of the lipid cores, narrowing the lumen (stenosis or plaque ruptures)
When is the window of opportunity for primary prevention?
Intermediate and advanced lesions
Life-style changes
Risk factor management
What is the intervention of arterial stenosis?
Balloon angioplasty PCI
What is the function of vascular endothelial cells?
Barrier function (to lipoproteins)
Leukocyte recruitment
What is the function of monocytes/macrophages?
Foam cell formation
Cytokine and growth factor release
Major source of free radicals
Metalloproteinases
What is the function of vascular smooth muscle cells?
Migration and proliferation within the tunica media
Collagen synthesis
Remodelling and fibrous cap formation
What is the function of platelets?
Thrombus generation - presents in acute MI, and unstable angina
Cytokine and growth factor release
What is the function of T-lymphocyte?
Macrophage activation
Which type of treatment during clinical trials had fewer major adverse cardiovascular events (MACE)?
Anti-Il-1 treatment
Which CD macrophage lysosome protein is brown-dyed when associated wot an antibody?
CD68
How are macrophage subtypes regulated?
Combination of transcription factors binding to regulatory sequences of DNA
What is the main function of inflammatory macrophages?
Phagocytose pathogens
What are the three classes of resident macrophages?
Alveolar resident macrophages
Osteoclasts
Spleen (reticuloendothelial)
Where are LDLs synthesised?
Within the liver
What do LDLs transport?
Cholesterol
Where is cholesterol abnormally deposited?
Arterial intima