Angina, which is also known as angina pectoris, occurs when the flow of blood through the coronary arteries to the heart muscle is insufficient to meet the heart’s oxygen demands, such as during physical activity.
Coronary heart disease is the most common cause of reduced blood flow to the heart in people with angina. Coronary heart disease is the build-up of fatty deposits on the inside of the coronary arteries causing them to become narrow and restricting the amount of blood flowing to the heart muscle.
There are two main types of angina:
- Stable angina: pain lasting 5-15 minutes that is relieved by angina medication. It usually has a trigger, such as physical exercise or exertion, anxiety or emotional stress, cold temperatures, or heavy meals
- Unstable angina: pain lasting longer than 15 minutes that may not be fully relieved by angina medication. It may indicate that you are having a heart attack. Unstable angina often occurs without a specific trigger.
Angina differs from a heart attack because the reduction in blood flow to the heart muscle is only temporary and does not result in damage to the heart muscle. During a heart attack, the interrupted blood flow can result in the heart muscle being damaged or destroyed.
People with angina, however, are at higher risk of having a heart attack. If you have been diagnosed with angina and you experience unstable angina or angina pain that is unusual, e.g. occurs when you are resting or wakes you up from sleep, you might be having a heart attack. You should dial 111 immediately.
Signs and symptoms
Angina symptoms are not always present because during times of low oxygen demand, e.g. when at rest, the heart muscle can function on the reduced amount of blood flow without triggering symptoms. However, when the demand for oxygen is increased, e.g. during exercise, the heart muscle cannot cope, and angina symptoms are triggered.
Signs and symptoms of angina include:
- chest pain or discomfort, often described as squeezing pressure, fullness, tightness, or a heavy weight in the centre of the chest
- pain or discomfort in the arms, neck, jaw, shoulder or back
- pain similar to indigestion or heartburn
- shortness of breath and tiredness
- nausea, sweating, and dizziness.
The severity, duration, and type of angina can vary. It is important to recognise new or different symptoms since they may signal unstable angina, or a heart attack.
In some cases women with angina may not experience classic chest pressure or discomfort symptoms, and this can lead to delays in seeking treatment. Instead they may experience a stabbing pain and/or some or all of the other symptoms listed above.
Angina is diagnosed by your doctor conducting a physical examination and asking about your symptoms and any risk factors, including whether there is a family history of heart disease.
Tests are available to help confirm a diagnosis of angina. These include:
- electrocardiogram (ECG): monitors patterns of the electrical signals in the heart to reveal whether the blood flow through the heart has been slowed or interrupted
- exercise stress test: involves conducting an ECG during exercise since it is easier to diagnose angina when the heart has to work harder
- echocardiogram: uses sound waves to produce moving images of the heart, which allows identification of angina-related problems
- chest x-ray: looks for other conditions that might be causing angina symptoms and to see if the heart is enlarged
- coronary angiography: uses x-ray imaging to obtain a detailed picture of the inside of the coronary arteries
- computerised tomography (CT) scan and magnetic resonance imaging (MRI): high-tech machines that collect multiple detailed images of the heart to show if the heart is enlarged or the coronary arteries are narrowed.
Treatment and prevention
The goals of treatment are to reduce the frequency and severity of angina symptoms and improve general heart health.
Because angina can be triggered by physical exertion, anxiety or emotional stress, cold weather, or eating a heavy meal, the following behavioural changes may help to alleviate angina symptoms:
- rest as soon as you feel symptoms coming on
- pace yourself and take regular breaks
- reduce and manage stress
- keep warm
- avoid eating large meals.
Risk factors for coronary artery disease include smoking, high blood pressure and cholesterol levels, diabetes, excess weight, and low levels of physical activity. Hence, the following lifestyle changes can help to minimise angina symptoms and improve your heart’s health:
- quit smoking and avoid second-hand smoke
- control high blood pressure or high blood cholesterol levels
- exercise moderately and regularly, especially heart disease-appropriate exercise (always consult a health professional before commencing a new exercise regime)
- maintain a healthy weight
- follow a heart disease-appropriate diet
- manage diabetes
- avoid drinking alcohol or do so in moderation.
Prescription medications may be necessary if lifestyle changes do not help your angina. The most commonly used medications for controlling angina symptoms are nitrates. They work by widening blood vessels, which allows more blood to reach the heart muscle. Nitrates come in short- and long-acting forms:
- Glyceryl trinitrate spray: droplets sprayed on or under the tongue are absorbed quickly from the mouth into the blood stream and provide almost immediate relief
- Glyceryl trinitrate tablets: placed under the tongue to dissolve or chewed and left to dissolve in the mouth, the tablets are absorbed into the blood stream from the lining of the mouth.
- Nitrate skin patches: provide a slow release of nitrate that is absorbed through the skin and provide the longest duration of effect of all the nitrate medications
- Nitrate tablets or capsules: provide nitrate that is absorbed through the stomach rather than the mouth and have a longer lasting effect than nitrate spray or tablets.
Other medications that may be prescribed to treat angina include beta-blockers which help the heart to pump more efficiently, and calcium antagonists which widen the arteries and allow more blood to flow to the heart.
Coronary artery bypass surgery (blood vessels taken from elsewhere in the body are used to bypass blocked coronary arteries) or coronary angioplasty (opening up the coronary arteries with a special balloon) may be required for severe angina. A coronary angiogram is used to determine whether surgery or angioplasty is necessary or possible.
Further information and support
Free phone: 0800 611 116
Free phone: 0800 863 375
ReferencesHeart Foundation (2016). Angina information sheet (PDF). Auckland: Heart Foundation of New Zealand. http://assets.heartfoundation.org.nz/shop/heart-healthcare/angina.pdf
Mayo Clinic (2016). Diseases and conditions: Angina (Web Page). Rochester, NY: Mayo Foundation for Medical Education and Research. http://www.mayoclinic.org/diseases-conditions/angina/basics/definition/con-20031194 [Accessed: 21/04/17]
Ministry of Health (2015). Angina (Web Page). Wellington: New Zealand Ministry of Health. http://www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/heart-disease/angina [Accessed 21/04/17]
O’Toole, M.T. (Ed.) (2013). Angina pectoris. Mosby’s Dictionary of Medicine, Nursing & Health Professions (9th ed.). St Louis, MI: Elsevier Mosby.
Created: April 2017