atheroma Flashcards
what is the definition of how a atheroma is formed (atherosclerosis)
Formation of focal elevated lesions (plaques) in intima of large and medium-sized arteries
how can atheroma effect the coronary arteries
the plaques narrow the lumen and lead to ischaemia - leads to angina due to MI
what is arteriosclerosis
not atheromatous
age related changes leading to vessel smooth muscle hypertrophy, duplication of internal elastic lamiae - decreased vessel diameter
what is the clinical significance of arteriosclerosis
higher frequency of cardiac, cerebral ischaemia
more apparent effect when CVS is stressed - haemorrhage, shock, infection
what are the 3 ‘‘steps’’ in the atheroma development
fatty streak
early atheromatous plaque
fully developed atheromatous plaque
what are early atheromatous plaque and where does it occur
smooth yellow patches in intima (innermost structure) laden with lipids
found in young adults onwards
what do early atheromatous plaques develop into
fully developed atheromatous plaque
what is a fatty streak in relation to atheroma development
earliest significant lesion, may disappear, in young children
may disappear, if not, may
what are fully developed atheromatous plaque
central lipid core with fibrous tissue cap - covered by arterial endothelium
what role does collage play in atheroma development
produced by smooth muscle cells in the cap - they provide structural strength
what inflammatory cells are in the cap - why
macrophages, t-lymphocytes, mast cells
recruited from arterial endothelium
what is in the central lipid core of a fully developed atheroma
its rich in cellular lipids
and debris from dead macrophages from the plaque
where do atheroma’s form
at arterial branching points/bifurcations
where there is TURBULENT FLOW
what occurs in late stage plaque development - clinical significance
extensive calcification of the atheroma
can be seen on CT scans
what is a complicated atheroma
features of a fully developed atheroma (lipid rich core, fibrous plaque)
there plaque ruptures and there is the formation of a thrombosis
what is the most important risk factors for the atherosclerosis
hypercholesterolaemia
hyperlipidaemia
what is hypercholesterolaemia
the presence of abnormal amount of cholesterol in the blood
what factors other than the two major ones effect atherosclerosis (5) and almost all cardiovascular disease
smoking hypertension diabetes mellitus male elderly
what is the two step process that causes the development of atheromatous plaques
injury to endothelial lining of artery
chronic inflammation and healing response - chronic leads to plaques forming
what are vulnerable atheromatous plaques
plaques that rupture with subsequent thrombosis
what are the distinct features of vulnerable atheromatous plaques
typically thin fibrous cap, large lipid core, prominent inflammation
what are the lifestyle changes that are preventative/therapeutic measure
smoking cessation BP control weight loss regular exercise dietary modifications
what is the most common drugs used in prevention - why
cholesterol lowering drugs
aspirin - inhibits platelet aggregation
what is the final treatment option
surgery
what happens after an injury to the epithelium
accumulation of lipoproteins
(LDL) in vessel wall
what happens after LDL accumulation
monocytes (white blood cells) adherer to endothelium surface and make foamy macrophages
what happens after monocyte adhesion
platelet adhesion - which then release factors that recruit smooth muscle
what happens after smooth muscle recruitment
smooth muscle proliferates
what are the two factors that effect endothelial damage
haemodynamic disturbances (turbulent flow)
hypercholesterolaemia ( reduce endothelial cell function)
what happens after smooth muscle proliferation
growth factors lead to synthesis of collagen and elastin to crate the cap
what is Progressive lumen narrowing due to high grade plaque stenosis
when there stenosis of over 50% of the vessels lumen - leading to critical reduction of blood flow in distal arterial bed
what is stable angina an example of
stenosed atheromatous coronary artery
what is unstable angina an example of
very sever stenosis - ischemia - pain at rest
what causes intermittent claudication (pain in legs)
peripheral artery disease
due to stenosis of ilea, femoral, popliteal arteries
what happens when there is acute atherothrombotic occlusion
Rupture exposes highly thrombogenic plaque contents (collagen, lipid, debris) to blood stream → activation of coagulation cascade and thrombotic occlusion in very short time - leading to a acute event
what happens if there is complete occlusion In a acute atherothrombotic occlusion - examples
Total occlusion → irreversible ischaemia → necrosis (infarction) of tissues
MI - coronary arteries
stroke - carotid, coronary arteries
what is the difference between atherosclerosis vs thrombosis
an atheroma is a deposit of fatty LDL tissue, where a thrombus is coagulation within the vessel
what is a atheromatous abdominal aortic aneurysm
a aneurism in the abdomen usually above the bifurcation of the descending aorta into the iliac arteries
asymptomatic in elderly
what happens if a atheromatous abdominal aortic aneurysm ruptures - when would this be
Sudden rupture → massive haemorrhage (high mortality)
Aneurysms bigger than 5cm - at high risk of rupture
what is an aneurysm
ballooning of a vessel caused by a localized, abnormal, weak spot on a blood vessel wall.
