Health and disease

• Coronary heart disease

  • The heart is made of cardiac muscle cells which need a supply of blood to deliver oxygen, glucose (for respiration) and other nutrients, and remove waste products such as carbon dioxide
  • The blood is supplied to the heart by the coronary arteries which branch off directly from the aorta and sit on the outside of the heart
• What is coronary heart disease (CHD)?

  It involves fatty material buildup in arteries
• What is the composition of the plaque in coronary heart disease?

  Layers of fatty material
• What happens if a coronary artery becomes blocked?

  Blood flow through the arteries is reduced
• What is the consequence of reduced blood flow to the heart muscle?

  It results in a lack of oxygen for the heart muscle
• What does partial blockage of coronary arteries cause?

  It creates restricted blood flow and angina
• What is angina?

  Severe chest pains from restricted blood flow
• What happens with complete blockage of a coronary artery?

  Cells cannot respire aerobically, causing a heart attack
• How does partial blockage differ from complete blockage in coronary heart disease?

  Partial blockage restricts blood flow; complete blockage stops it
• how can you treat coronary heart disease?

  • increasing the width of the lumen of the coronary arteries using a stent
  • prescribing statins to lower blood cholesterol
• What is the primary function of stents?

  To keep coronary arteries open
• How is a stent inserted into the body?

  A narrow tube is threaded through the groin
• What happens after the narrow tube is threaded to the blocked vessel?

  A tiny balloon is inflated
• What does the balloon do during the stent procedure?

  It pushes the stent against the artery wall
• What is the result of inflating the balloon in the stent procedure?

  Increases the width of the lumen
• What happens to the balloon and tube after the procedure?

  They are removed
• Why are stents considered effective for heart attack prevention?

  They increase blood flow to coronary arteries
• What is a positive aspect of stents?

  They last a long time
• What is a risk associated with stents?

  Risk of blood clots (thrombosis)
• How does the stent procedure impact the risk of heart attacks?

  It reduces the risk by widening the lumen
• What are the advantages of stents?

  • Effective at reducing the risk of heart attack as they widen the lumen and increase blood flow
  • Last a long time
  • Simple minor surgery to insert a stent
• What are the disadvantages of stents?

  • Risk of blood clots occurring
  • Risk of infection during surgery
  • Risk of damage to the blood vessel during surgery
• • What are statins and what do they do?Statins are drugs that are widely used to reduce the levels of fatty deposits (cholesterol) in the blood
  • They block an enzyme in the liver which is needed to make cholesterol
  • This slows down the rate of fatty material building up in the blood, reducing the risk of CHD occurring
• What are the advantages of statins?

  • reduce the levels of ‘bad’ cholesterol in the blood which reduces the risk of fatty deposits building up
  • increases the levels of ‘good’ cholesterol in the blood which remove ‘bad’ cholesterol circulating in the blood
• What are the disadvantages of statins?

  • Need to be taken regularly and long-term otherwise they are not as effective
  • Take some time to have an effect
  • Side effects of statins include muscle and joint pain, kidney problems and neurological issues
• What is the primary function of heart valves?

  Ensure one-way blood flow from ventricles
• Why might heart valves become faulty?

  Due to illness, old age, or heart attack
• What happens when heart valves stiffen?

  They prevent full opening for blood flow
• How does a faulty heart valve affect blood volume?

  It reduces the volume pumped by the heart
• What is a potential issue with a faulty heart valve?

  It might develop a leak
• What does a leak in a heart valve allow?

  Blood to flow back into the atria or ventricles
• How do faulty heart valves affect the heart's effectiveness?

  They reduce the effectiveness in pumping blood
• What are the surgical options for replacing faulty heart valves?

  • Biological valves from cows or pigs
  • Mechanical valves
• what are the advantages of biological replacement valves?

  • Highly effective
  • Less likely to leak
• What are the advantages of a mechanical valve?

  • Long lasting
  • Less need to replace
• what are the disadvantages of a biological valve?

  • Need to be replaced after 12-15 years
  • Risk of immune rejection
• What are the disadvantages of a mechanical valve?

  • Can increase the likelihood of blood clots
  • Lifelong need to take anticoagulant
• Heart transplants

  • In the case of heart failure a heart can be transplanted from a donor who has recently died
  • Waiting lists for organ transplants are often long, so an immediate solution can involve replacing the heart with an artificial heart made from plastic and metal
  • Artificial hearts may be used to:
  • keep patients alive while waiting for a heart transplant, 
  • allow the heart to rest as an aid to recovery
• Advantages of artificial hearts

  • Shorter waiting times
  • Less chance of the patient‘s immune system rejecting it
• Disadvantages of artificial hearts

  • Do not work as well as real hearts
  • Increases risk of blood clots leading to increase chance of stroke