pathophysiology of acs Flashcards
acs with st elevatoon?
troponin & ck elevated
nonstemi?
troponin elevated or not
coronary artery disease?
Most commonly due to coronary artery atheroma
Other coronary artery diseases:
Coronary artery spasm
Arteritis
Embolism
Congenital anomaly
Coronary artery dissecting aneurysm
Syphilitic aortitis
aha type 1?
non specific intimal thickening
aha type 2. fatty streaks
ulcerated complicated plaque?
thrombosis of plaque, involvement of media, thrombus
3 mechhanisms of atheroma occlusion?
- Thrombosis on complicated atheroma
- Haemorrhage into plaque
- Rupture of “vulnerable plaque”
recanalised thrombus?
Recanalized thrombus
End-stage of a thrombus. The blood clot (thrombus) is replaced by connective tissue with many newly formed channels. If these channels reestablish the continuity of the original vessel, blood may flow at a rate adequate to maintain perfusion. Note calcification
haemorrhage into plaque?
bleeding in the moddle of a plaque
ruptureof vulnerable plaque?
Stable plaque
Vulnerable plaque
Concept of remodelling
stable plaque?
thick fibrous collagen cap, few inflammatory cells
vulnerable plaque?
Loss of collagen and smooth muscle= thin fibrous cap Inflammation-
matrix degrading proteases
Weaken fibrous cap
glagov phenomenon?
Positive remodelling outward = compensatory remodeling : Glagov phenomenon
lumen diameter retained. no angina. thin fibrous cap
negative remodelling?
negative remodelling no dilatation
angina?
more than 70% narrowing
Stary Fuster classification
growing of arterial brnaches in atherosclerosis to accomodate?
adventitial vasa-vasorum
macrophage quantification score
score 0 - <5 macs
Score 1 - 6-25 macs
Score 2 - >25 macs
signs of intra plaque hemorraheg?
lipid core hemorrhage
re blood cells and fibrin
erythrocytes
inflammation
intraplaque hemorraheg?
Conversion of a stable, asymptomatic lesion to an unstable, ruptured plaque involves many processes, the most studied of which is inflammation, cellular breakdown, and expansion of the acellular, lipid rich, necrotic core.
Commonly believed that death of macrophages and SM foam cells, in addition to the aggregation of lipoproteins, contribute to the accumulation of extracellular free cholesterol within unstable plaques.
Intraplaque hemorrhage plays a role in the expansion of core of plaques though the relative importance of this vs. other mechanisms by which plaque burden increases is uncertain
how does the vessel respond to a plaque formation?
As plaque accumulates, the arterial wall often reacts by remodeling. As atherosclerosis progresses toward the more severe stages pictured on the right, the lumen remains constant because of compensatory expansion of the arterial wall. Eventually, however, in more severe stages of the disease, the artery is unable to expand further and the lumen begins to narrow.
The same process may work in reverse with disease regression. That is, plaque can be removed from the arterial wall with little change in lumen size. Therefore, the mildly narrowed lumen may be a less sensitive marker for the progression or regression of disease than direct estimates of plaque size.
postivie remodelling?
EEM and contour increases and allows the plaque to push against the walls and keep the luemn enlarged. I.E. plaque isn’t a [problem.