1. Atherosclerosis

2. Atherosclerosis Most common form of vascular disease
Narrowing of the lumen
Caused by a build up plaque in the tunica intima

3. Lumen: the inside space of a tubular structure (ex. blood vessel)
Plaque: build up of cholesterol and other substances in the tunica intima

4. Atherosclerosis ©http://cache.eb.com/eb/image?id=98483&rendTypeId=4

5. Atherosclerosis ©http://www. nlm. nih

6. Atherosclerosis of the Coronary Artery ©http://www. uphs. upenn

7. Atherosclerosis with Thrombus (Blood Clot) ©http://www. uwcvb

9. How does this occur?
Fat enters the area of the endothelial cells of the tunica intima
What type of lipid or fat causes this plaque build up?
Cholesterol

10. Cholesterol Produced by the liver and is found in saturated fats
Some cholesterol is needed for good health
It is the basis for many hormones
Forms cell membranes

11. It becomes a problem when there is too much cholesterol in the bloodstream
Hypercholesterolemia

12. Coronary Heart Disease ©http://www. texasheartinstitute

13. Cholesterol is carried through the bloodstream by lipoproteins
There are two types of lipoprotein carriers:
HDL
LDL

14. HDL: high density lipoprotein
“Good” type of cholesterol
Does not build up on the walls of arteries

15. Thought to protect from heart disease by removing plaque and taking it back to the liver where it can be passed from the body
This is now being questioned in the scientific community

16. LDL: Low density lipoprotein
“Bad” cholesterol
Accumulates in the arteries causing a build up
A clot (THROMBUS) can form near the plaque and block blood flow

17. ©

18. Cholesterol
Can be measured with a blood test

19. What Causes Plaque to Build Up on the Walls of Arteries?
Inflammation of the tunica intima occurs
May be caused by excessive irritation or a bacteria

20. Macrophages move in to remove the misplaced fat
LDL deposits cholesterol into the inflamed or injured areas of the tunica intima
Macrophages move in to remove the misplaced fat
Attempt to engulf the fat-laden cells

21. As macrophages engulf lipids, they look like foam
Hence the name FOAM CELLS

22. Foam Cells

23. Foam cells die and remain in the blood vessel
Smooth muscle cells and endothelial cells continue to proliferate creating a fibrous cap over the lesion

24. Processes continues and the lumen is narrowed

25. Atherosclerosis ©http://cache.eb.com/eb/image?id=98483&rendTypeId=4

26. In observing the atheroma, you may see cholesterol clefts
Cholesterol cleft: a space caused by the dissolving of cholesterol crystals in an atheroma

28. Foam Cells and a Cholesterol Cleft Seen in Atheromatous Plaque ©

30. Narrowing of an Artery ©http://d. yimg. com/origin1. lifestyles. yahoo

31. Atheroma ©http://www.heartzine.com/thumbs/atherosclerosis.jpg

32. Plaque that builds up deeper in the artery, between the intima and the media is called VULNERABLE PLAQUE
The film covering the plaque may rupture and cause a clot that could occlude the artery

33. Vulnerable Plaque ©http://www. texasheartinstitute

34. Vulnerable Plaque ©http://www. texasheartinstitute

35. Vulnerable plaque may be even more dangerous than a build up in the intima

36. Factors that Contribute to the Rate of Atherosclerosis
Diet
Fat intake
Saturated fats, trans-fats, and dietary cholesterol are all problematic

37. The liver produces enough cholesterol for cellular structures and functions
Any additional intake of fat can create problems

38. Saturated Fat ©http://www. nlm. nih

39. Heredity
Genetics are the biggest factor
Ex. Your genetic makeup may cause your liver to produce too much cholesterol

40. Hypertension
High blood pressure (the silent killer)
Increased pressure on your artery walls damage your arteries, which can speed up the accumulation of fatty deposits

41. Hypertension ©http://www. medmarketplace. com/images/HighBloodPressure

42. Diabetes
High blood sugar contributes to high LDL cholesterol and low HDL cholesterol
High blood sugar also damages the lining of your arteries

43. Lack of exercise
Regular cardio is beneficial, but not a huge gain

44. Smoking
Nicotine is a potent vasoconstrictor
Increases heart rate
Damages the walls of your blood vessels, making them likely to accumulate fatty deposits

45. Gender
Estrogen regulates the amount of cholesterol the liver produces
Lowers LDL and increases HDL

46. Treatment for Atherosclerosis
Coronary by-pass operation
Surgery reroutes or bypasses the clogged artery to improve blood flow and oxygen

47. Surgeons take a vessel from somewhere else in the body and make a detour around the occluded vessel
Gortex is also used

48. Coronary Artery Bypass ©http://media. allrefer

49. Coronary Artery Bypass ©http://www. taxus-stent

50. Balloon angioplasty with stent
Stent: cage-like wire that holds the lumen open

51. Stent ©http://heart.image-animation.com/ANGIOPLASTY-STENT-1.jpg

52. Stent ©http://heart.image-animation.com/ANGIOPLASTY-STENT-3.jpg

53. Stent ©http://www.taxus-stent.com/images/045g_StentV1_EN_150.jpg

55. Problem? Body tends to scar over the stent: restenosis
This is more than just a covering of endothelial cells—actual scaring that narrows the lumen

56. Solution Drug coated stent
Same type of stent, but coated with an anti-mitotic drug
Lasts 3-31/2 weeks by inhibiting the mitotic ability
After 3 weeks, endothelial cells cover stent without the scaring: fibroblast
Keeps lumen open

57. What is the problem with this?
New study shows that if we prevent the growth of scar tissue over the metal, people have a higher incidence of blood clots
How does it cause clots?
Platelets hit and tear on bare metal releasing enzymes that create clots

58. Patients are also given an anti-coagulant to prevent blood clots

59. Beta-Catheter
Once used to clear plaque build up with beta particles
Problem?
Eradication of normal tissue and formation of scar tissue cutting off the blood supply

60. Now used (sparingly) to clear the overgrowth of normal tissue from a stent after angioplasty

61. Basic fibroblast growth factor AND
Percutaneous myocardial revascularization
Used together and only done in extreme situations

62. Cardiologist uses a laser catheter to bore channels inside the heart
Catheter is sent through the femoral artery and into the left ventricle to the ischemic tissue (“oxygen starved”)
The hurt muscle (around the channel) sends out a signal to make new capillaries

63. The fibroblast growth factor is administered to stimulate blood vessel differentiation

64. Percutaneous myocardial Revascularization ©http://images. google

65. Blood Vessel Layers

66. Healthy Artery

67. Atherosclerosis ©http://www. chelationtherapyonline

68. Atheroma with Thrombus

69. Atherosclerotic Plaque https://secure. health. utas. edu

70. Atherosclerotic Plaque

71. http://images. google. com/imgres. imgurl=http://www. technion. ac

72. Cholesterol Clefts in an Atheroma