Lecture 17: Pathology of CAD Flashcards
Top three regions for atherosclerosis
- Lower aorta; 2. Coronaries; 3. Femorals, popliteals
Describe what happens to the monocytes…What causes all this?
Capture, roll, arrest and diapedesis into subendothelial space; cytokine production from damaged endothelial cells
Once absorbed into endothelial space, a monocyte becomes a…how?
Macrophage foam cell; engulfing LDL particles
What is the earliest recognizable form of atherosclerosis?
Fatty streaks
What are the six (3 –> 3) key features of plaque progression?
Inflammation, neovascularization, intra-plaque hemorrhage –> lipid core expansion, oxidative stress, apoptosis
Describe plaque neovascularization and three types
Vasa vasorum proliferate as neovessels: 1. Vasa vasorum interna, 2. Vasa vasorum externa, 3. Venous vasa vasorum
What is the danger of plaque neovascularization (2)?
Neovessels are fragile –> intraplaque hemorrhage –> 1) larger plaque size and 2) free hemoglobin increases oxidative stress
Type 1 AHA Class
Eccentric intimal thickening (no lipid), some isolated foam cells
Type II AHA Class
Foam cells (intracellular lipids)
Type III AHA Class
Type II lesion + some extracellular lipid pools
Type IV AHA Class
Fibrous cap and lipid pool
Type VA AHA Class
Larger cap, larger lipid core (lipid rich)
Type VB AHA Class
Lipid core with dystrophic calcification (calcific)
Type VC AHA Class
Lipid is replaced by fibro-collagenous tissue (fibrotic)
Type VI AHA Class
Fibrous cap disrupted, thrombus associated, intra-plaque hemorrhage
Which types can produce symptoms?
Type IV - VII (early)
Which decade are Types I and II?
1st
Which decade are Types III and IV?
3rd
Which decade are Types V and VI?
4th
Positive plaque remodeling: definition and associated with…
Increase in plaque size and External Elastic Membrane (EEM) area; Unstable lipid rich plaque, allowing considerable plaque expansion despite normal luminal size
Negative plaque remodeling : definition and associated with…
Decrease in plaque size and External Elastic Membrane (EEM) area; Diminished plaque size with reduction in lumen size
Three complications of plaque morphology
Rupture-thrombosis, erosion-thrombosis, calcific nodule
Define plaque thrombosis
Thrombogenic necrotic lipid core gets exposed to the flowing blood and results in thrombus formation
Define plaque erosion
The luminal thrombus overlies area that lacks surface endothelium but does not communicate with the lipid core
Define calcific nodules
Plaques with calcified nodule protruding into the lumen through a disrupted thin fibrous cap (FC), with secondary thrombus formation
Three clinical phase possibilities of coronary atherosclerosis
- Wall weakening/mural thrombosis –> aneurysm and rupture; 2. Plaque rupture/hemorrhage –> occlusion by thrombus; 3. Plaque growth –> critical stenosis
Stenting can lead to…
Restenosis via neoatherosclerosis due to deposition of ECM via myofibroblasts (from vessel wall injury)
In vein grafts, atherosclerotic lesions are…They lack?
Densely fibrotic; lipid core
