Cardiovascular Diseases Revision
Coronary Heart Disease
The heart has a network of vessels called the coronary arteries that supply the cells of the heart with everything they need, such as oxygen. The muscle cells of the heart use oxygen in respiration to produce the energy required for muscle contraction and therefore keep the heart beating.
Coronary heart disease (CHD) is when the coronary arteries get blocked by layers of fatty build up (made from ‘bad’ LDL cholesterol), narrowing the lumen of the vessel. This restricts the flow of blood, limits the amount of oxygen reaching the cells and can ultimately cause a heart attack.
Stents are tubes that are inserted into peoples arteries and used to treat people with coronary heart disease. The stents hold the arteries open, allowing blood to flow through and access respiring muscle cells.
Stents reduce the risk of patients with the disease having a heart attack and remain effective for a long time. The recovery time for the operation is relatively small but the surgery itself comes with risk of complications and infections. There is also an additional risk of blood clots called thrombosis near the stent.
Statins are drugs that reduce the amount of ‘bad’ or LDL cholesterol in the blood. This prevents fatty deposits forming and stops vessels getting blocked.
Statins reduce the risk of strokes, coronary heart disease and heart attacks and increase the levels of ‘good’ or HDL cholesterol in the blood. However:
- The patient must remember to take the drug regularly in order for them to be effective and there is a risk that they could be forgotten.
- They can cause various side effects such as headaches, joint pain and kidney problems.
- They do not take effect immediately.
Faulty Heart Valves
Some people have faulty heart valves. This could mean the valve is leaky and blood flows where it shouldn’t or the valve is stiff and amount of blood that gets pumped is reduced.
People with severely faulty heart valves can have their valves replaced with either biological valves from other humans and mammals or man-made mechanical valves.
Valve replacement is a safer surgery than a whole heart transplant but there is a risk of problems with blood clotting.
In the case of heart failure, the patient can be treated by a whole heart transplant (or heart and lungs if they are both diseased).
The transplanted organs usually come from a recently deceased donor. There is a high demand for transplants and they are only available after people have died so there are often very long waiting lists. While patients are waiting, artificial hearts can be used to keep the patients alive. Artificial hearts can also be used to give the heart a rest and therefore aid in its recovery.
Artificial hearts are manufactured so patients don’t have to wait for someone to die for one to become available and there is less chance of the body rejecting it as it is made of metals and plastics (the body will not recognise it as foreign).
However, they do not work as well as real hearts and parts wear out more easily. There is also an increased chance of blood clots and therefore strokes in an artificial heart as the blood doesn’t flow through as easily. To aid the flow of blood, patients must take blood thinning drugs but this can cause serious problems if they are accidently hurt.
Cardiovascular Diseases Example Questions
Question 1: Explain how stents can reduce the risk of a heart attack in people with coronary heart disease.
Stents squash the fatty deposits in the coronary arteries and hold them open which lets blood flow through easily.
This ensures oxygen is supplied to the muscle cells of the heart and so reduces the risk of a heart attack.
Question 2: What are statins and how do they prevent coronary heart disease?
Statins are drugs that reduce the amount of ‘bad’/LDL cholesterol in the blood.
So less fatty deposits form.
Blood can flow more easily through the arteries.
Question 3: Explain 2 advantages of artificial heart transplants over biological heart transplants.
Any 2 from:
- Artificial hearts are manufactured so are readily available. This means there is no waiting list and you don’t have to wait for a donor to die.
- Can be used to keep patient alive while the heart has time to rest and recover.
- Less chance of rejection from the body as made out of metals and plastics.
Gold Standard Education
£19.99 /month. Cancel anytime