MEDRADSC 3J03 Lecture Notes - Lecture 13: Coronary Artery Disease, Angina Pectoris, Coronary Circulation
11 Nov 2019
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Lecture #13: Pathologies of the Circulatory & Lymphatic Systems
Left Sided Coronary Artery Disease
1. Circumflex Artery -> Left Ventricle & Left Atrium
2. Anterior Interventricular Artery or Left Anterior Descending (LAD) Artery -> both ventricles
- Coronary arteries arise form aortic root
- Can be L or R dominant
- Heart is being supplied by ⅔ from left coronary artery and remaining ⅓ from the right - Left Dominance
- Left anterior descending stenosis is more detrimental than someone who has a right dominant
- Left anterior descending or circumflex - better to have a small stenosis here than left main
- We have “extra” contributory vessels, or collateral circulation - safety mechanism if there is a stenosis somewhere else,
retrograde flow to supply the damaged heart tissue
Image
- No flow beyond the blockage
- Part of segment that the blood is serving will die (myocardial infarction)
Coronary Circulation
Right Coronary Artery
1. Right Coronary Artery -> Right Atrium
2. Marginal Artery -> Right Ventricle
3. Posterior Interventricular Artery or Posterior Descending Artery -> both Ventricles
- Coronary of the R is easier to see compared to the L - doesn't have the size or length of vessels that the L side; in the
shape of a C when contrast is injected
- 1 main branch with posterior branches
CAD
- Overall name for 3 forms of cardiac disease, which results from insufficient coronary blood flow:
1. Atherosclerotic Heart Disease: plaque builds & leads to narrowing or completely occlude; narrowing = less
blood supply to heart muscle & then gent angina pectoris
2. Angina Pectoris: in order to alleviate the pain they take nitroglycerine orally
3. Myocardial Infarction
A. Conventional Selective Coronary Angiography: showing the
L Anterior Descending (LAD) & Circumflex (Cx) coronary
arteries
B. CT volume rendering of L Main Coronary Artery with its
branches, the LAD, & Left Cx arteries
Arterio vs Athero
Arteriosclerosis
Atherosclerosis
- Group of disorders resulting in thickening &
inelasticity of arterial walls
- Aka “Hardening of the Arteries”
- Most common form of “arterio” affects the large & medium
sized arteries (Aorta, branches, coronaries, brain)
- Common cause of CAD
- Slow progressive narrowing of coronaries (years); ppl don't
know that they have it, ignore signs, diff signs b/n genders;
won’t know until it is extremely bad
- Dependent - myocardium slowly deprived of blood supply
Atherosclerosis
- A progressive disease that begins in childhood when “fatty streaks”/lipids are deposited in vessel intima
- ie. development of an “atheroma”
- Fibrous encapsulation creates fibrous plaques - causing the inelasticity of the vessels
- Plaque elevates the lining of the vessel -> roughens surface & narrows lumen (common at bends or junction of vessels
where the turbulence is greatest)
- Final Steps: (image)
