myocardial infarction and stroke Flashcards
3 phases of atherosclerosis (plaque build up)
- formation of fatty streaks
- atheroma formation (platelets attach to endothelium)
- plaque formation (high bp, low blood flow, damage vessel walls)
MOD risk for atherosclerosis
SOSTAD
- smoking
- obesity
- sedentery lifestyle
- type 2 diabetes
- alcohol
- diet
NON-MOD risk for atherosclerosis
- age
- gender
- family history
- personality charcterisitcs
- increased trigylcerides
- hypertension
risk of developing atherosclerosis for a given individual
- High levels of blood lipids (total cholestrol greater than 6mmol/L increases risk 2x)
- Hypertension (systolic SP>140mmHg and untreated, increases risk 5x)
- Smoking (increase 2x)
- Diabetes mellitus (increases risk 2x)
- Genetics (influence HDL:LDL levels)
if hypoxia leads to death of a cell, by which mechanism is it mostly likely to die?
necrosis (cell swelling and bursts)
formations of thrombus includes:
formation of thrombus then MIS (agina), MIN,S
- large arteries - transport blood
- medium arteries - control blood to organs
- small arteries - regulate capilary blood flow
how macrophages contribute to inflammation and plaque formation in
atherosclerosis
- monocytes form into Inflammatory macrophages enter the tunica initima and become foam cells which release proinflammatory cytokines then fatty streak to nerotic core formate in the intima causing plaques and inflammed reaction.
The plaque is composed of: - thin fibrous cap
- large lipid pool
- cholesterol
developing a weak cap due to low collagen.
clinical characteristics of angina pectoris
- left side sharp chest pain lasting for 10-15min
- temporary lack of blood to heart muscle
- spasm of coronary arteries
ischaemic stroke
due to thrombosis in a cerebral vessel. 80% of strokes
clinical characteristic of myocardial
infarction
myocardial infarction- decrease or complete block of blood flow to the myocardium.
- not due to cardiac workload
- results in cell death (necrosis)
- blocking of arteries by thombi
causes of haemorrhagic stroke
- hypertension
- aneurysm (small berry in the artery)
- thrombocytopenia (low platelets)
- arteriovenous malformation
- cerebral amyloid angiopathy
haemorrhagic stroke
due to ruptured vessel, resulting in bleeding.
3 causes of ischaemic strokes
SET
- sudden obstruction of cerebral artery
- embolism often from the heart or carotid artery
- thrombosis forming on an atherosclerotic narrowing of large artery.
what is a treatment of ischaemic stroke?
- thrombolysis - a theraputic breakdown of fibrin within a blood clot.
What happens when a person has an ischaemic stroke?
- blood flow reduced by 15% in ischaemic core and up to 40% in the ischaemic penumbra
- too much release of glutamate (neurotoxic)
- too much intracellular calcium causes the release of inflammatory mediators and destructive enzymes.
