Atherosclerosis lecture 12

Question 1

Describe Atherosclerosis

Answer 1

chronic inflammatory, fibre-proliferatvie disease of the artery wall. It is associated with and possible intimated by the accumulation and oxidation of circulating lipids, in particular cholesterol.

Primary Atherosclerosis - chronic inflammatory, fibre-proliferatvie disease of the artery wall - lasts decades

Transplant Atherosclerosis = narrowing of arteries at the point of enlargement of transplanted organs - lasts months/years

Restenosis (thickening of artery wall) after cardiopulmonary bypass = last month/years

Atherosclerosis is normal in arterial tree due to presence of bifications/branching points where laminar flow is stopped.
Thickening occurs under endothelial cells and onto of internal elastic lamina

Question 2

Describe each type of Atherosclerosis

Answer 2

1) Fatty streak - There is a fatty streak (doesn’t impinge on narrowing of artery) within the intima which has accumulated form cells, lipids, T cells and macrophages. Complex plaques derive from fatty streaks
2) Intermediate or fibrofatty lesion - There is lots of smooth muscle cells which causes the connective tissue matrix to form
3) Advances fibrous plaque - smooth muscle cells generate the fibrous cap. Fibrous cap is important as it has lots of connective tissue to resit the high pressure the blood flow causes. There is a necrotic core which is made up of dead cells (foam cells) which release their lipid into the necrotic core. There is a large and stable (few inflammatory cells and low lipid content) plaque which restricts blood flow.

Question 3

Embolic mural events associated with advanced fibrous plaques -

Answer 3

A venerable plaque is present (High lipid content and lots of inflammatory cells and have a thin fibrous cap). The venerable plaque ruptures and exposes prothromobtic contents to blood and you get formation of a thrombus, thrombus goes downstream and can block blood flow

Question 4

Diseases associated with atheroma distribution

Answer 4

Peripheral vascular disease in legs/periphary
Cause -
- intermittent claudication (arteries block blood flow), ulceration (due to bad blood flow, lack of immune cells so ulceration occurs), gangrene (if blood flow stops, tissue dies and gangrene occurs)

Coronary heart disease
Causes -
Actute angina (chest pain due to poor blood flow), unstable angina (started formation of thrombus), myocardial infarction

Cerebrovascualr disease - stoke due to embolic events

Question 5

Therapeutic options for Atherosclerosis are

Answer 5

Controlling risk factors - hypertension controlled by Ca channel blockers, ACE inhibitors

Can decrease circulating lipids by decreasing cholesterol synthesis in liver (statins) - anti inflammatory, improve endothelial cell function

Type 2 diabetes - increases chance of stroke, increase weight loss from obesity , decrease hypertension

Angina pectoris - vasodilator therapy - nitroglycerin (vasodilator by opening up blood vessels so more blood goes to heart)

Surgery - coronary artery bypass, femoral artery bypass, angioplasty and stenting (widening blocked or narrowed coronary arteries - using a ballon to stretch artery.

Consuming omega 3 fatty acids from oily fish etc. Decrease cardiovascular disease greatly over time. Increases plasma , platelets and monocytes and lymphocytes. Can also reduce stroke