Cardiovascular Disease

• Cardiovascular disease is a term used to describe diseases of the heart or blood vessels, e.g. coronary hear disease
• Stents keep arteries open
• Coronary heart disease is when the coronary arteries that supply the blood to the muscle of the heart gets blocked by layers of fatty material build up. This causes the arteries to become more narrow, so blood flow is restricted and there's 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 the blood can pass through to the heart muscles. This keeps the person's heart beating (and the person 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

  
• On the down side, 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
• Statins reduce cholesterol in the blood
• Cholesterol is an essential lipid that your body produces and needs to function properly. However, too much of a certain type of cholesterol (known as 'bad' or LDL cholesterol) can cause health problems
• Having too much 'bad' cholesterol (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 'bad' cholesterol (LDL cholesterol) present in the bloodstream. This slows down the rate of fatty deposits forming
• Statins have advantages and disadvantages
• Advantages of statins:

  • By reducing the amount of 'bad' cholesterol (LDL cholesterol) in the blood, statins can reduce the risk of strokes, coronary heart disease and heart attacks
  • As well as reducing the amount of 'bad' cholesterol (LDL cholesterol), statins can increase the amount of a beneficial type of cholesterol (known as 'good' cholesterol or HDL cholesterol) in your bloodstream. This type can remove 'bad' cholesterol from the blood
  • Some studies suggest that statins may also help prevent some other diseases
• Disadvantages of statins:

  • Statins are a long-term drug that must be taken regularly. There's the risk that someone could forget to take them
  • Statins can sometimes cause negative side effects, e.g. headaches. Some of these side effects can be serious, e.g. kidney failure, liver damage and memory loss
  • The effect of statins ins't instant. It takes time for their effect to kick in
• An artificial heart can pump blood around the body
• If a patient has heart failure, doctors may perform a heart transplant (or heart and lungs transplant if the lungs are also diseased) 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 the 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 main 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 fit an artificial heart (as with transplant surgery) can lead to bleeding and infection. Also, artificial hearts don't work as well as healthy natural ones - parts of the heart could 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
• Faulty heart valves can be replaced with biological or mechanical valves
• 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 ther mammals - these are biological valves. Or they can be man-made - these are mechanical valves
• Replacing a valve is a much less dramatic procedure than a whole heart transplant. But fitting artificial valves is still major surgery and there still can be problems with blood clots
• Artificial blood can keep you alive in an emergency
• When someone loses a lot of blood, e.g. in an accident, their heart can still pump the remaining red blood cells around (to get oxygen to their organs), as long as the volume of their blood can be topped up
• Artificial blood is a blood substitute, e.g. a salt solution (''saline''), 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. It not, the patient will need a blood transfusion
• Ideally, an artificial blood product could replace the function of the lost red blood cells, so that there's no need for a blood transfusion. Scientists are currently working on products that can do this