Cardiovascular Disease

• What are the three stages of cardiovascular disease?


  1. Atheroma Formation, 2. Atheroma = Aneurysm and Thrombosis, 3. Interrupted Blood Flow to Heart = Myocardial Infarction
• Describe how atheroma forms.

  • Damage to endothelium of artery (e.g. by high blood pressure)
  • WBCs (mostly macrophages) and lipids from blood clump together under lining to form fatty streaks
  • Overtime, WBCs, lipids, and connective tissue build up & harden to form fibrous plaque called atheroma
• What effect does atheroma have on blood flow?

  Atheroma blocks the lumen of the artery and restricts blood flow, causing blood pressure to increase.
• Name the two types of diseases that affect arteries.

  1. Aneurysm, 2. Thrombosis
• What is an aneurysm and how does it occur?

  • Aneurysm is a balloon-like swelling of an artery.
  • Occurs when atheroma plaques damage and weaken arteries.
  • Narrow arteries increase blood pressure.
  • High pressure blood pushes inner layers of artery through outer elastic layer to form aneurysm.
• What may happen to an aneurysm?

  An aneurysm may burst and cause massive bleeding.
• What is thrombosis and how does it occur?

  • Thrombosis is the formation of a blood clot.
  • Occurs when an atheroma plaque bursts through the endothelium of an artery.
  • This damages the artery wall and leaves a rough surface.
  • Platelets and fibrin accumulate at the site of damage to form a blood clot (thrombus).
• What can a blood clot do and what can this lead to?

  A blood clot can cause complete blockage of an artery or can become dislodged and block a blood vessel elsewhere.
• Describe how a myocardial infarction (heart attack) occurs.

  1. Coronary artery is blocked.
  2. Area of heart muscle is cut off from blood supply, leading to no oxygen.
  3. This causes myocardial infarction (heart attack).
• How can the widening of blood vessels reduce ventricular blood pressure?

  Widening blood vessels creates a larger lumen, which reduces blood pressure and decreases friction.