Cardio Flashcards
atherosclerosis definition
atheromatous deposits in the intima of arteries and inner layer fibrosis
characteristics of atherosclerosis
intimal thickening
narrowing of lumen
lipid accumulation
3 components of athersoclerotic plaque
ECM - collagen, elastin, proteoglycans
cells - smooth muscle cells, macrophages, T lymphocytes
lipids - both intra and extracellular
modifiable risk factors
t2dm, hypertension, smoking, hypercholesterol
non-modifiable
age, sex, family history,
factors that make a plaque VULNERABLE (4)
- high amounts of lipid/foam cells
- thin fibrous cap
- decreased amount of smooth muscle cells
- large clusters of inflamm cells
most common sites of atherosclerosis
infrarenal abdominal aorta, abdo aorta»_space;> thoracic.
coronarys, popliteal, circle of willis
where along a blood vessel is atherosclerosis most likely to form?
ostia (origins) of major branches as there will be increased turbulent flow - oscillatory shear stress - atherogenic
an occlusive intracoronoary thrombus overlying a disrupted atherosclerotic plaque, leading to myocardial ischaemia
MI
pathogenesis of MI
atherosclerotic plaque rupture –> platelet activation –> thrombosis –> vasospasm
how long must ischaemia last before irreversible damage?
20-40min
myocyte death
mechanical complications of MI
- contractile dysfunction - cardiogenic shock
- ventricular dysfunction - cardiogenic shock
- LV infarct and papillary muscle damage - mitral regurg
- cardiac rupture - R>L shunts, haemopericardium
> 4 weeks post MI with persistent ST elevation
ventricular aneurysm
how many patients develop arrythmia post MI
90%
arrythmia causing death in <24hr post MI
VF
chest pain, fevers, and effusion weeks after MI
Dressler’s syndrome
histological findings 6hrs post MI
normal
Most commonly affected vessel in MI
LAD 50%
RCA 40%
LC 10-20%
evolution of MI (cells)
no more atherogenic food
neutrophils, macrophages, angioblasts, fibroblasts