coronary heart disease 2.2.4

• coronary heart disease is when the coronary arteries that supply the blood to the muscle of the heart get slowly blocked by layers of fatty material building up
• this causes the arteries to become narrow so blood flow is restricted and theres a lack of oxygen to the heart muscle which can result in a heart attack
• health problems caused by a reduction in blood supply to the heart muscle include:

  • pain due to lack of oxygen
  • heart attacks
  • death due to no oxygen reaching the brain
• stents are tubes that are inserted inside arteries, they keep them open, making sure blood can pass through to the heart muscles which keeps the persons heart beating
• 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, theres a risk of complications during the operation (heart attack), and a risk of infection from surgery, there is also the risk of patients developing a blood clot near the stent called thrombosis
• stents:

  1. the stent is inserted using a catheta
  2. the balloon is inflated which pushes the stent open and pushes the fat against the wall of the coronary artery
  3. the catheta is removed which leaves the permanent stent behind
• statins are widely used to reduce blood cholesterol levels which slows down the rate of fatty material deposit
• statins are drugs that have to be taken regularly long term
• patient may need a heart transplant when the heart fails completely and a pacemaker isnt enough to save someone
• if donor organs arent available right away or they arent the best option, then doctors may fit an artificial heart
• artificial hearts are mechanical devices that pump blood for a person whose own heart has failed, they are usually only a temporary fix while waiting for a transplant or during recovery to give the heart a rest, however in some cases they can be permanent they need a lot of machinery and often people have to stay in hospital
• the main advantage of artificial hearts is that they are less likely to be rejected because they are made from metals or plastics so the body doesnt attack them the same way they would with living tissue
• however the disadvantages of artificial hearts is that:

  • surgery can lead to bleeding and infection
  • parts of the heart could wear out or a motor could fail
  • blood doesnt flow through as smoothly which can cause blood clots and strokes
  • the patient has to take drugs to think their blood which can cause problems if theyre in an accident
• the valves in the heart can be damaged or weakened by heart attacks, infection, pulmonary hypertension, or old age, the damage may cause the valve tissue to stiffen so it wont open properly, or a valve may become leaky, allowing blood to flow in both directions rather than just forwards, this means blood doesnt circulate as effectively as usual
• replacement valves can be ones taken from humans or other mammals eg cows or pigs (biological valves) or mam-made (mechanical valves)
• replacing a valve is a much less drastic procedure than a whole heart transplant but fitting artificial valves is still a major surgery and there can be problems with blood clots
• leaky valves can cause heart failure, irregular heartbeat or high blood pressure in the lungs vessels