Atheroma and Complications Flashcards
describe epidemiology of atheroma
common in developed world
most important arterial disease
ischaemic heart disease and stroke account for 1/3 of all deaths
describe risk factors of atheroma
cigarette smoking hypertension hyperlidiemia diabetes age - older sex - males genetics
describe pathology of atheroma
primary endothelial injury due to; smoking hypertension immune factors toxins viruses
accumulation of lipids and macrophages causing;
increased LDL
reduced HDL
production of VCAM, IL-1 and TNF
migration of smooth muscles causing production of;
PDGF, FGF, TGFalpha
increase in size
as atheromatous plaques enlarge, blood flow is compromised
describe complications of atheromatous plaques
as they progress, they become more complicated;
fatty streak
fibrofatty plaque
complicated plaque (overlying thrombus)
progression associated with further loss of luminal patency and arterial wall weakness
describe atheromatous narrowing of an artery progressing to a critcal disease
only likely to occur is;
it is the only artery supplying an organ or tissue (e.g. no collateral circulation)
artery diameter is small (e.g. coronary artery versus common iliac artery)
overall blood flow is reduced (e.g. cardiac failure)
describe complications of atheroma
stenosis thrombosis aneurysm dissection embolism
describe arterial stenosis
narrowing of arterial lumen
reduced elasticity
reduced flow in systole
tissue ischemia
can affect any artery;
coronary artery
carotid (tia, stroke, vascular dementia)
renal arteries (hypertension and renal failure)
peripheral arteries (claudication and foot/leg ischeamia)
describe clinical effects of cardiac ischemia
reduced exercise tolerance angina unstable angina MI cardiac failure
describe cardiac fibrosis
loss of cardiac myocytes
replacement by fibrous tissue
loss of contractility
reduced elasticity and filling
describe clinical effects of superadded thrombosis
MI
cerebral infarction
renal infarction
intestinal infarction
describe aneurysm formation
abnormal and persistent dilation of an artery due to a weakness in its wall
mycotic, atherosclerotic, dissecting, congenital, arteriovenous, traumatic, syphillitic
commonest site - abdominal aorta
describe complications of aneurysm
rupture thrombosis embolism pressure erosion of adjacent structures infection
describe arterial dissection
splitting within the media by flowing blood
middle age +/- atheroma
false lumen filled with blood within the media
sudden collapse and high mortality
describe other associations with aortic dissection
atheroma hypertension trauma coarctation marfan's pregnancy
describe embolism
both superadded thrombus and plaque material may break off and embolise usual targets; cerebral infarct renal infarct and renal failure lower limb infarction
