cardiovascular disease

• cardiovascular disease is a general term used to describe diseases associated with the heart and blood vessels
• cardiovascular disease includes:

  • aneurysms
  • thromboses
  • myocardial infarction
• most CV diseases starts with an atheroma formation
• coronary heart disease (CHD) is a type of CV disease. It occurs when the coronary arteries have lots of atheromas in them, which restricts blood flow to the heart muscle - can lead to myocardial infarction
• atheroma formation:

  • wall of an artery made up of several layers
  • endothelium (inner lining) usually smooth and unbroken
  • if damage occurs to the endothelium (e.g. by high BP)
  • white blood cells (mostly macrophages) and lipids (fat) from the blood clump together under the lining to form fatty streaks
  • over time - more WBC, lipids and connective tissue build up and harden to form a fibrous plaque called an atheroma
• an atheroma is a fibrous plaque that partially blocks the lumen of the artery and restricts blood flow, which causes blood pressure to increase
• deposits of fatty material, dead cells and WBC and connective tissue build up under the endothelium and push it out into the lumen - atheroma

  lumen shrinks as artery wall swells - more difficult for blood to pass through
• An aneurysm is a balloon like swelling of the artery:

  • starts with the formation of atheromas
  • atheroma plaques damage and weaken arteries
  • also narrow arteries, increasing blood pressure
  • when blood travels through a weakened artery at high pressure
  • it may push the inner layers of the artery through the outer elastic layer to form an aneurysm - may burst
  • burst = haemorrhage
• Thrombosis is the formation of a blood clot:

  • starts with formation of an atheroma
  • atheroma plaque can rupture (burst through) the endothelium of an artery
  • damages artery wall and leaves a rough surface
  • platelets and fibrin (protein) accumulate at site of damage and form a blood clot - thrombus
  • blood clot can cause a complete blockage of the artery or can become dislodged and block a blood vessel elsewhere in the body
  • debris from rupture can cause another blood clot to form further down artery
• myocardial infarction = heart attach:

  • heart muscle is supplied with blood by coronary arteries
  • blood contains oxygen needed by heart muscles to carry out respiration
  • if coronary artery becomes completely blocked (e.g. by blood clot) - area of heart muscle totally cut off from blood supply, receiving no oxygen
  • causes a myocardial infarction
• a heart attack can cause damage and death of heart muscle
• symptoms of a heart attack:

  • pain in the chest and upper body
  • shortness of breath
  • sweating
  • if large areas of heart muscle affected - complete heart failure can occur - can be fatal
• a risk factor is something that increases your chances of developing a disease
• there are many things that increase your risk of getting atheromas in arteries:

  • smoking
  • too much salt in diet
• high blood pressure:

  • increases risk of damage to artery walls
  • damaged walls have increased risk of atheroma formation causing further increase in BP
  • atheromas can also cause blood clots to form
  • blood clot could block flow of blood to the heart muscle - possibly = myocardial infarction
  • anything that increases BP also increases risk of CV disease
  • e.g. being overweight, not exercising and excessive alcohol consumption
• • not exercising/ overweight
  • high BP
  • atheroma formation
  • blood clots
  • myocardial infarction
• High blood cholesterol and poor diet:

  • if blood cholesterol level high (above 240 mg per 100 cm3)
  • risk of CV disease increased
  • bc cholesterol is one of main constituents of fatty deposits that form atheromas
  • atheromas can lead to increased blood pressure and blood clots - could cause myocardial infarction
  • diet high in saturated fat associated with high blood cholesterol
  • diet high in salt also increases risk of CV disease bc increases risk of high BP
• • diet high in saturated fat/ salt
  • high blood cholesterol/ high BP
  • atheroma formation
  • blood clots
  • myocardial infarction
• Cigarette smoking:

  • both carbon monoxide and nicotine found in cig smoke increase risk of CV disease and MCIF
  • carbon monoxide combines with haemoglobin and reduces amount of oxygen transported in the blood and so reduces amount of oxygen available to tissues
  • if heart muscle doesn't receive enough oxygen - can lead to heart attack
  • smoking also decreases amount of antioxidants in blood - important for protecting cells from damage
  • fewer antioxidants means cell damage in coronary artery walls is more likely - can lead to atheroma formation
• CV disease does not just affect heart - e.g. blood clot in an artery in the brain can cause a stroke
• • smoking
  • carbon monoxide
  • less oxygen in blood
  • less oxygen to tissues
  • MCIF
• • smoking
  • fewer antioxidants
  • damage to coronary artery walls
  • atheroma formation
  • MCIF
• Reducing the risk:

  • most of these factors within our control
  • person can choose to smoke, eat fatty foods
  • however some risk factors can't be controlled e.g. genetic predisposition to coronary heart disease/ having high BP as a result of another condition e.g. some forms of diabetes
  • even so risk of developing CVD can be reduced by removing as many risk factors as can
• other common risk factors

  • obesity
  • lack of physical exercise
  • ethnic background (people of South Asian or African Caribbean background may have a greater risk of certain forms of CVD)
  • age - old more at risk
  • sex - men more at risk