Pathophysiology of atheroma 1 Flashcards
What is atheroma?
It is formation of focal elevated lesions (plaques) on intima of large and medium-sized arteries.
What are serious consequences of atheroma?
In coronary arteries, atheromatous plaques the narrow lumen causing ischaemia, the serious consequence of this is:
- Angina due to myocardial ischaemia
What is atheroma complicated by?
thromboembolism
What is arteriosclerosis?
It is NOT ATHEROMATOUS
It is a age related change in muscular arteries
What illnesses does arteriosclerosis contribute to in the elderly?
It contributes to high frequency of cardiac, cerebral, colonic and renal ischaemia.
When are the clinical effects of arteriosclerosis most apparent?
When CVS is further stressed by haemorrhage, major surgery, infection and shock.
What causes arteriosclerosis?
- Smooth muscle hypertrophy
- A reduplication of internal elastic laminae
- Intimal fibrosis - decrease in vessel diameter
What is fatty streak?
- It is the earliest significant lesion
- Usually seen in young children
- It is a yellow linear elevation of intimal lining
- It comprises of masses of lipid laden macrophages
- It has no clinical significant as it may disappear
What is early atheromatous plaque?
- It is found n young adults onwards
- It is smooth yellow patches in intima
- Lipid-laden macrophages
- Progresses to established plaque
What is a fully developed atheromatous plaque?
Central lipid core with fibrous tissue cap is covered by arterial endothelium
Central lipid core is rich in cellular lipids/debris derived from macrophages (died in plaque)
Where do inflammatory cells reside in?
Inflammatory cells (macrophages, t-lymphocytes, mast cells) reside in fibrous cap.
They are recruited from arterial endothelium
What do collagens in the cap provide?
Collages in cap provide structural strength and are produced by smooth muscle cells
What is the texture of a fully developed atheromatous plaque?
It is soft, highly thrombogenic and often rim of foamy macrophages.
What is a marker for atherosclerosis in angiograms/CT?
An extensive dystrophic calcification, which occurs late in plaque development
Where does the fully developed atheromatous plaque form at?
Arterial branching points/bifurcations (turbulent flow)
Late stage plaques are confluent and cover large areas
