Lecture 13- Heart Disease Flashcards
describe atherosclerosis
o Monocytes adhere to endothelial surface proteins (adhesion molecules)–>monocytes migrate into intima, accumulate cholesterol, form foam cells –> release growth factors–>triggers proliferation of SMC–>lipid accumulates
o Plaque develops over decades, acute complications occur suddenly i.e. rupture of plaque (don’t know what triggers this to happen)
long term management of atherosclerosis and effects
lowering of LDL-C by statins (HMG CoA reductase inhibitors)
- reduces lipid content in plaque, inflammation and thrombosis
- relative risk reduction about 24%
lowering BP, quit smoking, control diabetes
Compare CHD event rates in secondary and primary prevention trials
secondary
- stronger the statin, the lower the mortality rate drops compared to the placebo
- event rate is so high- statin saves lives
primary
- event rate is less compared to secondary
- when event rate is already really low, then taking statin to reduce risk is not really worth it
- only worth it with other risk factors combined with elevated LDL
examples of acute coronary syndromes
- heart attack
- MI- death of myocardium
- unstable angina- presence of chest pain without myocardial damage
- sudden onset of chest pain
- myocardial damage (troponin, CK in blood)
definition difference between secondary and primary prevention trials
secondary- had an attack then put the patient on statins
primary- high LDL cholesterol but not yet had heart attack
what is a culprit lesion?
often mild plaque–>little calcification
may expand outwards in days/weeks
pathology of acute MI with reference to occlusive coronary thrombi
thrombus forms on ruptured atheromatous plaque- suddenly occludes or severely narrows artery
why do plaques rupture?
controversial
- macrophages may be responsible for decreased collagen synthesis, increased collagen breakdown by MMPs, production of procoagulants so induce thrombosis when plaque ruptures
- remember- one localised plaque ruptures, not multiple
ways to manage acute coronary syndromes
recognition- patient, ambulance, medical urgent reperfusion - thrombolysis- IV - stent (percutaneous coronary intervention) into artery to open it wide then give drugs to reduce thrombolysis - anticoagulants, antiplatelet agents -lipid lowering
most heart valve disease is ?
degenerative
valvular heart disease used be a consequence of ?
rheumatic fever
what is rheumatic fever?
immune response to strep pyogenes, antibody cross-reactivity-
Type II hypersensitivity
age group common for rheumatic fever?
children 6-15 yrs
clinical features of rheumatic fever?
heart murmur–>valvular damage especially to mitral valve
- fever, arthritis, rash, skin nodules
methods for RhF prevention
penicillin and public health
