Cornary Heart Disease Flashcards
What are the 2 main forms of lipoproteins?
High Density Lipoproteins (HDL)
Low Density Lipoproteins
What is the role of LDL?
carries lipids in the blood to cells lining the blood vessels
(including the cells lining the arteries, which can lead to the development of fatty streaks within in blood vessel lining)
What is the role of HDL?
transports lipids from cells to the liver, allowing them to be metabolised
What is the ideal ratio for HDL-LDL
HDL>LDL
HDL = healthier
Describe the structure of a blood vessel
Inner layer- epithelia called endothelium
Middle layer- smooth muscle
Outer layer- connective tissue
what is Atherosclerosis?
thickening or hardening of the arteries caused by a build-up of plaque in the inner lining
How may initial injury to the endothelium occur during atherosclerosis?
increased LDL, decreased HDL, high BP, diabetes etc
Describe the development of atherosclerosis?
- Initial injury to endothelium
- Endothelium becomes inflamed
- Macrophages are attracted to the area and release inflamatorry mediaters (CRP, TNF-α)
What is the effect of plaque accumulation?
- the fibrous plaque can calcify and protrude into the vessel lumen, decreasing blood flow
- some plaques are unstable and may rupture
what is ischemia
reduction in blood supply-
therefore reduction in oxygen delivery to cardiac muscle
what is angina?
pain produced as a result of hypoxia (lack of oxygen) to the myocardium
what type of pain does angina cause?
typically chest pain, pain in the neck, jaw or arms
how can angina be treated?
- Angioplasty
- Vasodilationors: to decrease smooth muscle contraction in coronary artery wall
- Cornoary artery bypass graft
what does increased troponin levels indicate?
cardiac damage
what is an NSTEMI?
a less severe heart attack as there is only partial occlusion of the cornoary artery
no ST elevation
what is a STEMI?
a severe heart attack caused by complete occlusion of the cornoary artery
Name some treatments for athersclerosis
- weight loss
- angioplasty
- thrombolyitic drugs
- cornoary artery bypass graft
- aerobic exercise
-dietary modification
what is heart failure
the inability of the heart to pump enough blood to meet the body’s need.
what can happen if fibrous plaques calcify?
the fibrous plaque can protude into the vessel lumen and decrease blood flow
what is renin?
Renin is an enzyme released by the juxtaglomerular cells of the kidneys in response to low blood pressure, low sodium levels, or sympathetic nervous system activation.
what is the main function of renin?
it converts angiotensinogen into angiotensinsin 1
what does the Angiotensin-Converting Enzyme (ACE) do?
it converts angiotensin I into angiotensin II
*primarilly in the lungs
what is the role of angiotensin II?
it regulates blood pressure by causing vasoconstriction and stimulating the release of aldosterone
what is the role of aldosterone?
promotes sodium and water retention in the kidneys, thereby increasing blood volume and blood pressure.
what is cardiac output?
the volume of blood the heart pumps per minute
what is the formula for cardiac output?
CO = SV X HR
What is heart rate?
the number of heart beats per minute
what is stroke volume?
the amount of blood pumped by the heart with each beat
*The difference between end-diastolic volume and end-systolic volume = SV
what is end-diastolic volume?
The volume of blood in the ventricles at the end of diastole, just before the heart contracts (during the relaxation phase of the cardiac cycle)
what is end-systolic volume?
The volume of blood remaining in the ventricles at the end of systole, after the heart has contracted and ejected blood into the arteries.
what is VO2 max?
refers to the maximum volume of oxygen an individual can utilize during intense exercise
