11 - Atherosclerosis - Clinical Manifestations Flashcards
when does the majority of coronary blood flow occur?
during diastole
how can heart increase it’s O2 consumption?
increasing coronary blood flow
coronary arteries arise from ___
sinuses of valvsalva at root of aorta
major chemical mediator of increased coronary blood flow
adenosine (breakdown product of ATP)
how does hypoperfusion / inc metabolic needs increase coronary blood flow?
anaerobic metab > local acidosis and lactate buildup > more adenosine > more CBF
how much autonomic control over coronary blood flow is there?
relatively little - mostly just indirect
how much does the heart rely on anaerobic metabolism under normal conditions?
virtually none - usually exclusively aerobic metabolism
3 determinants of myocardial O2 demand (in order most>least important)
HR, wall tension, contractility
surrogate measure for wall stress when estimating MV02
systolic BP
key drug for reducing MVO2
beta blockers
variant angina / Prinzmental’s angina
rare - resting chest discomfort w/ transient ST elevation due to coronary spasm
4 classes of drugs that are good for CAD pts
beta blockers
nitrates
CaCBs
anti platelet drugs (ex aspirin)
coated stents are better why, but what new disadvantage do they have
much lower rate of restenosing, but have a higher risk for late thrombosis
what medications should be given for the first year after getting a coated stent
aspirin and clopidogrel to prevent platelet aggregation
in diabetic pts, which is preferred - CABG or PCI?
CABG - more complete revascularization