Heart Disorders

• Hypertension is defined as an abnormally high blood pressure – either systolic, diastolic or both (e.g. > 140/90 mmHg)
• Common causes of hypertension include a sedentary lifestyle, salt or fat-rich diets, excessive alcohol or tobacco use
• High blood pressure can also be secondary to other conditions (e.g. kidney disease) or caused by some medications
• Hypertension itself does not cause symptoms but in the long-term leads to consequences caused by narrowing blood vessels
• Thrombosis is the formation of a clot within a blood vessel that forms part of the circulatory system
• Thrombosis occurs in arteries when the vessels are damaged as a result of the deposition of cholesterol (atherosclerosis)
• Atheromas (fat deposits) develop in the arteries and significantly reduce the diameter of the vessel (leading to hypertension)
• The high blood pressure damages the arterial wall, forming lesions known as atherosclerotic plaques
• If a plaque ruptures, blood clotting is triggered, forming a thrombus that restricts blood flow
• If the thrombus becomes dislodged it becomes an embolus and can cause blockage at another site
• Thrombosis in the coronary arteries leads to heart attacks, while thrombosis in the brain causes strokes
• Risk factors for coronary heart disease (CHD) include:

  • Age – Blood vessels become less flexible with advancing age
  • Genetics – Having hypertension predisposes individuals to developing CHD
  • Obesity – Being overweight places an additional strain on the heart
  • Diseases – Certain diseases increase the risk of CHD (e.g. diabetes)
  • Diet – Diets rich in saturated fats, salts, and alcohol increase the risk
  • Exercise – Sedentary lifestyles increase the risk of developing CHD
  • Sex – Males are at a greater risk due to lower estrogen levels
  • Smoking – Nicotine causes vasoconstriction, raising blood pressure