2.4 Coronary Heart Disease

• Coronary Heart Disease

  layers of fatty deposits build up inside the coronary arteries, narrowing them

  • reduces the flow of blood through the coronary arteries
  • resulting in a lack of oxygen for the heart muscle.
• Stents

  a mesh tube that is inserted into the blood vessel to open it up and restore blood flow
• Statins

  a medication which lowers blood cholesterol levels - reduces chances of fatty build ups
• Stents - Pros and Cons

  pros

  • effective - offers long term solution
  • quick surgery recovery time

  cons

  • surgery - risks of infection or complications
  • blood clot near stent - thrombosis
• Statins - Pros and Cons

  pros

  • reduce risks - strokes, CHD, heart attacks
  • increase beneficial cholesterol - HDL
  • may also help prevent other diseases

  cons

  • have to be taken regularly - may forget
  • negative side effects - headache --> kidney failure
  • is not an instant effect
• What could happen to heart valves?

  • become faulty - preventing the valve from opening fully (tissue stiffens)
  • might develop a leak - blood flows in both directions - does not circulate as effectively
• Biological valve

  humans and other mammals

  • more likely to wear out
• Mechanical valve

  strong, durable materials

  • last longer
• Disadvantages of Artificial Valves

  • require surgery
  • ongoing risk of blood clots
• Artificial Hearts

  mechanical devices which pump blood for a person - own heart failed

  • temporary fix - until donor found
  • help recover - heart able to rest and heal
• Artificial Heart - Pros

  • less likely to be rejected by immune system - made from metals and plastics - does not recognise them as foreign - will not attack in the same way comparing to living tissue
• Artificial Heart - Cons

  • surgery - risk of infection and bleeding
  • do not function as well - worn out - electric motor fails
  • blood doesn't flow as smoothly - cause blood clots - strokes
  • has to take drugs - thin blood
• Artificial Blood

  blood substitution - saline solution (salt)

  • increases volume to circulatory system - heart can still pump
  • lacks red blood cells - cannot transport oxygen - 1/3
  • gives enough time to produce new blood cells - safe
• Blood Transfusion

  received real blood - from donor

  contains red blood cells