The pathology of cardiovascular diseases

• Angina


  Chest pain occurring when blood supply to heart muscle is restricted
• Atheroma


  Swelling on inner wall of artery; made up of fatty material and connective tissue
• Atherosclerosis


  Condition in which atheromas clog the arteries
• Cardiovascular diseases


  Diseases affecting the heart and circulation
• Cholesterol


  Lipid molecule needed for cell membranes and to synthesise steroid hormones
• Deep vein thrombosis (DVT)


  Blood clot in a deep vein, often in the leg
• Embolus


  Any detached mass of material carried by the circulation
• Fibrin


  Protein that helps to clot blood
• Fibrinogen


  Blood protein that is converted to fibrin during blood clotting process
• Heart attack


  Medical emergency when blood supply to heart muscle is blocked
• High-density lipoprotein (HDL)


  Carries excess cholesterol away from body cells and artery surfaces to the liver for elimination
• LDL receptor


  Receptor that recognises LDLs and promotes their uptake
• Lipoprotein


  Assembly of protein and lipid that allows movement of lipids in water and through membranes
• Low-density lipoprotein (LDL)


  Carries cholesterol to body cells; if cells have enough cholesterol, LDL may deposit cholesterol, leading to atheroma in arteries
• Myocardial infarction (MI)


  Medical term for a heart attack
• Peripheral vascular disorder


  Condition caused by blockage to arteries other than coronary arteries, the aorta or arteries in the brain
• Prothrombin


  Blood component which is converted to thrombin during clotting
• Pulmonary embolism


  An embolism (blood clot) in the pulmonary circulation
• Thrombin


  Produced from prothrombin during blood clotting
• Thrombosis


  Blood clot within a blood vessel
• Atherosclerosis is the accumulation of fatty material (consisting mainly of cholesterol, fibrous material and calcium) forming an atheroma or plaque beneath the endothelium
• As the atheroma grows the artery thickens and loses its elasticity
• The diameter of the lumen becomes reduced and blood flow becomes restricted resulting in increased blood pressure
• Atherosclerosis is the root cause of various cardiovascular diseases (CVD) angina, heart attack, stroke and peripheral vascular disease
• Thrombosis


  1. Prothrombin (inactive) is converted to thrombin

  2. Thrombin causes fibrinogen to form fibrin threads

  3. Fibrin threads form a meshwork that clots the blood and seals the wound

  4. Provides a scaffold for scar tissue formation
• If a thrombus forms in an artery


  It has the potential to block the artery and cause death of the cells it supplies
• A thrombosis in a coronary artery is known as a coronary thrombosis
• Coronary thrombosis


  Can lead to a myocardial infarction (heart attack)
• If an embolus blocks a coronary artery it may lead to a heart attack, and if it blocks an artery in the brain it may lead to a stroke
• Peripheral vascular disease (PVD) is narrowing of the arteries due to atherosclerosis of arteries other than those of the heart or brain
• The arteries of the legs are most commonly affected in PVD, causing pain in the leg muscles due to limited oxygen supply
• Deep Vein Thrombosis (DVT)


  A blood clot that forms in a deep vein, most commonly in the leg
• Common causes of DVT

  • Obesity
  • Smoking
  • Pregnancy
  • Lack of exercise
  • Long periods of inactivity
• If a thrombus in a vein breaks free, the clot (embolus) will pass to the right side of the heart and then to the lungs, potentially causing a pulmonary embolism</b>
• Cholesterol is a type of lipid, synthesised by all cells, although 25% of total production takes place in the liver
• Low Density Lipoproteins (LDL)


  Carry cholesterol to body cells, which can lead to deposition in arteries forming atheromas
• High Density Lipoproteins (HDL)


  Transport excess cholesterol from body cells back to the liver for elimination, preventing accumulation in the blood
• A higher ratio of HDL to LDL will result in lower blood cholesterol and reduced chance of atherosclerosis
• Ways to increase HDL levels


  • Physical activity
  • Maintaining a healthy weight
  • Low fat diet
• Statins


  Drugs that reduce blood cholesterol by inhibiting its synthesis by liver cells