Cardiovascular Disease

• Cardiovascular disease is a term used to describe diseases of the heart or blood vessels, for example coronary heart disease.
• Coronary heart disease is when the coronary arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up. This causes the arteries to become narrow, so blood flow is restricted and there is a lack of oxygen to the heart muscle - this can result in a heart attack.
• Stents are tubes that are inserted inside arteries. They keep them open, making sure blood can pass though to the heart muscle. This keeps the person's heart beating and therefore keeping them alive.
• Stents are a way of lowering the risk of a heart attack in people with coronary heart disease. They are effective for a long time and the recovery time from the surgery is relatively quick.
• When using stents, there is a risk of complications during the operation (e.g. heart attack) and a risk of infection from surgery. There is also the risk of patients developing a blood clot near the stent - this is called thrombosis.
• Cholesterol is an essential lipid that your body produces and needs to function properly. However, too much of a certain type of cholesterol (LDL cholesterol) can cause health problems.
• Having too much LDL cholesterol in the bloodstream can cause fatty deposits to form inside arteries, which can lead to coronary heart disease.
• Statins are drugs that can reduce the amount of LDL cholesterol present in the bloodstream. This slows down the rate of fatty deposits forming.
• Advantages of statins include:

  1. They reduce the amount of LDL cholesterol in the blood which reduces the risk of strokes, coronary heart disease and heart attacks.
  2. They increase the amount of HDL cholesterol in your bloodstream which removes LDL cholesterol from the blood.
• Disadvantages of statins include:

  1. They are a long term drug that must be taken regularly so there is a risk that someone could forget to take them.
  2. They can cause negative side effects like headaches or even kidney failure, liver damage and memory loss.
  3. The effect isn't instant and they take their time to kick in.
• If a patient has heart failure, doctors perform a heart transplant using donor organs from people who have recently died. However, if donor organs aren't available right away or they're not the best option, doctors may fit an artificial heart.
• Artificial hearts are mechanical devices that pump blood for a person whose own heart has failed. They're usually only used as a temporary fix, to keep a person alive until a donor heart can be found or to help a person recover by allowing the heart to rest and heal. In some cases though, they're used as a permanent fix, which reduces the need for a donor heart.
• The advantage of artificial hearts is that they're less likely to be rejected by the body's immune system than a donor heart. This is because they're made from metals or plastics, so the body doesn't recognise them as 'foreign' and attack in the same way as it does with living tissue.
• Surgery to fix an artificial heart can lead to bleeding and infection. Artificial hearts also don't work as well as healthy natural ones because parts of the heart can wear out or the electrical motor could fail. Blood doesn't flow through artificial hearts as smoothly, which can cause blood clots and lead to strokes. The patient has to take drugs to thin their blood and make sure this doesn't happen, which can cause problems with bleeding if they're hurt in an accident.
• The valves in the heart can be damaged or weakened by heart attacks, infection or old age. The damage may cause the valve tissue to stiffen, so it won't open properly. Or a valve may become leaky, allowing blood to flow in both directions rather than just forward. This means that blood doesn't circulate as effectively as normal.
• Severe valve damage can be treated by replacing the valve. Replacement valves can be ones taken from humans or other mammals (e.g. cows or pigs) - these are biological valves. Or they can be man made - these are mechanical valves.
• Replacing a valve is a much less drastic procedure than a whole heart transplant. But fitting artificial valves is still major surgery and there can still be problems with blood clots.
• When someone loses a lot of blood, their heart can still pump the remaining red blood cells around as long as the volume of their blood can be topped up.
• Artificial blood is a blood substitute which is used to replace the lost volume of blood. It's safe (if no air bubbles get into the blood) and can keep people alive even if they lose 2/3 of their red blood cells. This may give the patient enough time to produce new blood cells. If not, the patient will need a blood transfusion.