Angina refers to pain felt in the chest that usually occurs as a result of coronary heart disease. Some individuals may feel the pain in their arm, abdomen, neck or jaw. The pain is often brought on during physical activity, emotional upset or after eating a meal and subsides after a short while. Stable angina, however, causes pain that is constant.
Angina is caused by the heart muscle or myocardium being deprived of adequate oxygen and nutrients due to a shortage in the supply of blood from the coronary arteries. This leads to areas of the heart supplied by these arteries becoming damaged and dying off.
Atherosclerosis is one of the leading causes of angina and is the basic underlying pathology of coronary artery disease. In atherosclerosis, factors such as smoking, high blood pressure and elevated triglyceride and cholesterol levels can eventually damage the endothelial lining of arteries. When this occurs, platelets, lipoproteins, fats and cellular debris start to accumulate at the the site of damage, the presence of which can stimulate the arterial cells to produce other substances that then attract more cells to the area. These accumulating substances start to form a plaque. This plaque thickens the endothelial wall significantly, narrowing the space in the artery for blood to flow through, which reduces the oxygen supply to the heart muscles.
As the heart muscles pump throughout a person’s entire life time, these muscles need a continuous and constant supply of oxygenated blood. Without this supply, parts of the muscle can quickly become damaged and die. The term used to describe this lack of oxygen supply to the muscle is ischemia. In severe obstruction of the arteries, there is massive ischemia and the heart muscles undergoes necrosis or death, which is the basic pathology of a heart attack or myocardial infarction.
As a symptom of coronary artery disease, angina can act as a warning signal for myocardial infarction or a heart attack. Angina is often treated with glyceryl trinitrate to relieve symptoms. This medication belongs to a group of drugs called the nitrates, which relax and dilate blood vessels, increasing blood supply to the heart. The medication is available as a tablet that can be dissolved underneath the tongue.
Beta blockers are another effective therapy in the treatment of angina. These agents regulate the heart beat, slowing it down and making it beat more gently. This lowers the heart’s demand for oxygen which can prevent or reduce the frequency of angina. Examples of beta blockers include atenolol and metoprolol.
Antiplatelet drugs such as aspirin are used to prevent platelet aggregation and the formation of plaques, which can help reduce the likelihood of a heart attack. Treatment also involves the correction of factors that increase the risk of coronary artery disease such as high blood pressure and raised cholesterol levels.
Reviewed by Sally Robertson, BSc