Patho: Cardiovascular Flashcards
What is Coronary Artery Disease?
A condition that includes “Angina Petoris” and “myocardial Infarction”
These result from decreased O2 to the heart
How does the coronary circulation work?
It is the circulation around the heart muscle (myocardium)
It is Intermittent and Pulsating.
Blood flow is ineffective during ventricular contraction b/c of the compression by the contracting myocardium to pump out blood.
What is Anastomoses?
-They are Networks of fusing arteries in the coronary circulation.
This helps explain why, if the cornary ateries are bocked, how the heart can still manage to get nutrients.
-Regular aerobic (w/ O2) exercise contributes to cardiovascular fitness by stiulating the development of collateral channels.
What are collateral channels?
Secondary channels for blood flow.
What is ARTeriosclerosis?
A term used referring to conditions that cause arterial changes.
- Degenerative changes to the arteries and arterioles >50yrs olds.
- Leads to ischemia and necrosis in various tissues
Common in the Kidney: Renal failire, brain:Stroke, and heart: MI.
Patho of ARTeriosclerosis
- Aging makes the vessel walls lose elasticity.
- Narrowed lumens are caused by the vessel walls hardening and thickening.
- Ischemia can result from complete obstruction of the vessles
What is ATHEROsclerosis
A condition which involves the presence of “Atheromas” which blocks the circulation and weakens the arteries.
What are Atheromas?
- Deposits of lipids, cells, fibrin, and cellular debris.
- Often have attached clots.
- Form inside the vessel walls, primarily in the large arteries, the coronary arteries, carotid arteries.
- They occlude blood flow.
- They initially start off as fatty streaks, then becomes larger and begins to project into the lumen of the vessel.
Patho of ATHEROsclerosis
1) The formation of atheromas beings with endothelial injury to the arteries (young age)
2) injury causes inflammation, leading to the accumulation of WBC’s and lipids at the surface of the lining and inside the layer of smooth muscle.
3) Smooth muscle will proiliferate in resonse to this, and will lead to the formation of plaque.
4) Lipids and fibrous tissue (to replace damaged tissue) then gather and accumulate, increasing the size of the plaque.
5) As plaque increases in size, inflammation continues and the cyles of inflammation and deposit continues.
(Formation of Atheromas from injury–> inflammation and accumulation of WBC and lipids –> Proliferation as a response creating plaque –> accumulation of lipids and fibrous tissues –> plaque increases)
More patho of ATHEROsclerosis
- Blood flow progressively decreases b/c the lumen narrows and pressure increases (which could create an embolism)
- Plaque may rupture resulting in the formation of a clot and total obstruction of the vessel.
- Atheroma weakens the arterial wall reducing its elasticity.
- Loss in eleasticity forms a weak point in the wall of the vessel, making it susceptible to an aneuryam or hemorrhage of the vessel.
Inherent risk factors for ATHEROsclerosis
Genetics
-Cholesterol Balance
> 40yrs.
Gender: males when young, females when older (post menopause b/c no longer using cholesterol to make hormones)
Modifiable risk factors of ATHEROsclerosis
Diet: high in fatsLifestyle: Exercise (form anastmoses), vevous return
Obesity: best to lose weight.
Smoking: decr. HDL (bring cholesterol back to the liver), Incr. LDL (bad cholesterol that’s kept in the peripheral artieries), encourages clot formation, vasocontrictor.
Uncrontrolled BP: HTN –>damanes vessel walls.
Diabetes: Sugars and fats (Hyerlipidemia)
What is Angina Pectoris?
“Temporary myocardial ischemia”It is chest pain
-Results from an enlarged artheroma that causes a paritial obstruction to the coronary arteries.
Cause of Angina
Partial obstruction of coronary arteries leading to lack of oxygen to the cardiac muscle.
Due to:
- Impaired blood flow
- Cardiac demand for oxygen has increasd.
- Or a combo of the two.
Etiology of Angina
- Atherosclerosis
- Arteriosclerosis
- vasospam
- Myocardial hypertrophy (enlarged heart muscle which needs more oxygen which increased O2 demand and delivery)
- Severe anemia
- Respiratory disease
- Onset often requires exertion.