Coronary Heart Disease - non communicable

• • layers of fatty material build up in the coronary arteries, narrowing them
  • reduce their blood flow, results in lack of oxygen for the heart
  • can result in heart attack
• Atherosclerosis:

  • fat and cholesterol is deposited as plaque or atheroma in artery walls
• STENTS

  • used to widen narrowed arteries
  • some release drugs to prevent blood clots
• BYPASS SURGERY

  • use sections of veins from other parts of body to create a graft - alternate route for blood to flow to avoid the narrowed artery
• STENTS ADVANTAGES

  • cheap
  • less risky surgery, no general anaesthetic

  STENTS DISADVANTAGES

  • can't open blocked or very narrow arteries
  • can cause blood clots (so can atheroma)
  • tissue can grow over stent, ineffective
• BYPASS SURGERY ADVANTAGES

  • effective against completely blocked arteries

  BYPASS SURGERY DISADVANTAGES

  • expensive
  • risky surgery - open heart surgery
• Heart problems - leaky valves

  • can cause backflow of blood > heart won't pump blood as efficiently so less blood leaves heart
• MECHANICAL VALVES

  • titanium or polymers, last a long time
  • need medicine for the rest of life to prevent blood clotting around it
• BIOLOGICAL VALVES

  • based on valves from animals - pigs/cattle/human donors
  • work well, effective
  • last 12-15 years
  • anti - clotting medicine isn't needed
• Artificial pacemakers

  • cells in right atrium control heart beat (natural pacemaker cells)
  • electrical device implanted in chest, send strong and regular electrical signals to stimulate it to beat properly
  • some can stimulate it to beat faster in exercise
• Artificial blood ADVANTAGES

  • no risk of disease
  • readily available
  • long shelf life
  • doesn't always need to be refrigerated
  • no religious objections
  • can be good at carrying oxygen
• Artificial blood DISADVANTAGES

  • broken down quickly in body
  • doesn't clot
  • doesn't provide food/nutrients
  • can't defend against disease
  • can cause side effects