CARDIO Flashcards
Define atherosclerosis
Build up of plaque in the intima of an artery
What can an atherosclerotic plaque cause?
- Heart attack
- Stroke
- Gangrene
what are the risk factors for atherosclerosis?
- Family history
- Increasing age
- Smoking
- High serum cholesterol (LDL)
- Obesity
- Diabetes
- Hypertension
What are the constituents of an atheromatous plaque?
Lipid core
Necrotic debris
Connective tissue surrounded by foam cells
Fibrous cap
Lymphocytes
In which arteries would you most likely find an atheromatous plaque?
Peripheral and coronary arteries - circumflex, LAD and RCA
Focal distribution along the length
What histological layer of the artery may be thinned by an atheromatous plaque?
Media
What is the precursor for atherosclerosis?
Fatty streaks
What can cause chemoattractant release?
Endothelial cell injury
What is the function of chemoattractants?
Signal leukocytes and produce a concentration gradient
What is the function of leukocytes?
Leukocytes accumulate and migrate into vessel walls and release cytokines leading to inflammation
What inflammatory cytokines are found in plaques?
IL-1
IL-6
IFN-gamma
Describe the process of leukocyte recruitment
- Capture
- Rolling
- Slow rolling
- Adhesion
- Transmigration
What types of molecules are present during leukocyte recruitment?
- Chemoattractants
- Selectins (1-3)
- Integrins (3-5)
Describe the 5 steps of progression of atherosclerosis
- Fatty streaks
- Intermediate lesions
- Fibrous plaque/advanced lesions
- Plaque rupture
- Plaque erosion
At what age do fatty streaks begin to appear?
< 10 years old
What are the constituents of fatty streaks?
Foam cells and T lymphocytes within the intimal layer of the vessel wall
What are the constituents of intermediate lesions?
Foam cells
Smooth muscle cells
T lymphocytes
Platelet adhesion and aggregation
Extracellular lipid pools
What are the constituents of fibrous plaques?
Fibrous cap overlies lipid core and necrotic debris
Smooth muscle cells
Macrophages
Foam cells
T lymphocytes
What are fibrous plaques able to do?
Impede blood flow and they are prone to rupture
Why might a plaque rupture?
Fibrous plaques are constantly growing and receding
Fibrous cap has to be resorbed and redeposited in order to be maintained
If balance is shifted in favour of inflammatory condition, the cap becomes weak and the plaque ruptures
Thrombus formation and vessel occlusion
What the primary treatment for atherosclerosis?
Percutaneous Coronary Intervention (PCI)
What is the major limitation of PCI?
Restenosis
How can restenosis be avoided following PCI?
Drug eluting stents –> anti-proliferative and drugs that inhibit healing
What drugs can patients be started on following a PCI?
Aspirin - antiplatelet
Clopidogrel/Ticagrelor - inhibit P2Y12 ADP receptors on platelets
Statins - cholesterol lowering
Anti-inflammatory drugs - Colchicine, canakinumab