Cardiology Flashcards
what is the main problem with atherosclerosis
plaque rupture - thrombus formation and partial/complete arterial blockage leading to heart attack
what is the best known risk factor for coronary artery disease
age
risk factors for atherosclerosis
age, tobacco smoking, high serum cholesterol, obesity, diabetes, hypertension, family history
where are atherosclerotic plaques most commonly distributed
peripheral and coronary arteries
what factors might govern the distribution of atherosclerotic plaque
- changes in flow/turbulence (bifurcations)
- wall thickness
- altered gene expression
what is found within an atherosclerotic plaque
- lipid
- Necrotic core
- Connective tissue
- Fibrous cap
what are the outcomes of an atherosclerotic plaque
it will either occlude the vessel lumen or it could rupture
what inflammatory cytokines can be found in plaques
IL-1, IL-6, IL-8, IFN-y, TGF-b, MCP-1 and C reactive protein
what are the steps in leukocyte recruitment and movement through the vessel wall
Capture
Rolling
Slow Rolling
Firm adhesion
Transmigration
what are the features of a fatty streak
- the earliest lesion of atherosclerosis
- Appear at a very early age (<10 years)
- consist of aggregations of foam cells and T lymphocytes within the intimal layer of the vessel
what are intermediate lesions
they progress from the fatty streak, containing foam cells, vascular smooth muscle cells, T lymphocytes, and platelet adhesion. They also contain isolates pools of extracellular lipid
what are the features of a fibrous cap (or advanced lesions)
- impedes blood flow
- prone to rupture
- covered by a dense fibrous cap made from
extracellular matrix proteins or collagen and elastin - contains a lipid core and necrotic debris
- may be calcified
what does a fibrous cap contain
smooth muscle cells
macrophages
foam cells
T lymphocytes
what causes a plaque rupture
if the balance is shifted and there are high inflammatory conditions, and increased enzyme activity, the cap becomes weak and the plaque can rupture
what is plaque erosion
this is where lesions tend to be small early lesions. A thickened fibrous cap may lead to collagen triggering thrombosis. A platelet-rich clot may cover the luminal surface and there is a small lipid core
what is a red thrombus
where there are red blood cells and fibrin present
what is a white thrombus
when there are platelets and fibrinogen present
what are the clinical characteristics that predispose someone to a plaque rupture
dyslipidemia
hypertension
diabetes Mellitus
chronic kidney disease
multi vessel disease
what can be done when someone gets a ruptured plaque
- stent implantation
- distal embolisation
what are clinical characteristics which predispose someone to plaque erosion
smoking
being female
being younger than 50
having anterior ischemia
how is coronary artery disease treated
PCI - percutaneous coronary intervention
stent
what are coronary stents made of
stainless steel
what action does aspirin
it irreversibly inhibits platelet cyclo-oxygenase
what is the action of clopidogrel or ticagrelor
it inhibits P2Y12 ADP receptors on platelets and therefore has antiplatelet action