What is angina?
Angina causes crushing pain in the centre of the chest.
Angina pectoris is a phrase that comes from Latin and translates as 'tight chest'.
People with angina experience pain in the centre of the chest. The chest can feel constricted and tight, but the pain can also be oppressive, as if something is crushing your chest.
Pain starts in the center of the chest behind the breast bone (sternum) or on the left side of the front of the chest. It can spread out to other parts of your body like your arms and stomach.
Angina is often brought on by:
- physical exercise
- extreme cold
- a heavy meal.
Once these trigger factors stop, the pain tends to fade away quickly, usually within 10 minutes.
What causes angina?
In most cases, the cause of angina is coronary atherosclerosis: the thickening of arteries that supply blood, oxygen and nutrients to the heart.
This happens when fatty deposits, called plaques or atheroma, narrow the arteries over time and reduce blood flow to the heart.
Symptoms may only appear at times when your heart needs more blood supply, such as when you're stressed, exercising or climbing stairs.
As your heart tries to pump faster to meet your body's increased demands, the narrowed arteries struggle to keep up. The heart then receives too little oxygen, which causes pain in the heart that is felt as chest pain.
In severe cases this can also happen when the heart is at rest.
Are there any other causes?
Angina can be aggravated by other illnesses, including:
- a sustained fast heartbeat
- anaemia (thin blood)
- heart valve diseases such as severe aortic stenosis - a narrowing of the outflow valve of the heart
- thickening of the heart muscle (hypertrophy), which can be a result of high blood pressure over several years.
In rare cases, a severe spasm of a coronary artery can happen when there is relatively little narrowing from fatty deposits. The artery appears to be working normally, but is not. This is known as variant or Prinzmetal angina.
Types of angina
- Stable angina: chest pain is brought on when the heart has to work harder.
- Unstable angina: there is no pattern to chest pain and it can happen when the heart is resting. Symptoms are more severe than stable angina and pain tends to last longer.
- Variant angina: chest pain is caused by sudden artery spasm. This means pain can happen when the heart is at rest, more often in the early morning.
What are the risk factors?
All of us have fatty deposits in our arteries to some degree. Atherosclerosis can start as early as our 20s and increases with age.
But there are risk factors that are known to increase the development of fatty deposits that can cause your arteries to narrow.
- A family history of atherosclerosis.
- High levels of LDL cholesterol in the blood.
- High blood pressure.
- Being male.
- Lack of regular exercise.
What are the symptoms of angina?
Symptoms typically start during physical exertion or emotional stress. They are often worse in cold or windy weather and sometimes after big meals.
- A squeezing or heavy pressing sensation on the chest.
- Increased shortness of breath on exercise.
- A sense of heaviness or numbness in the arm, shoulder, elbow or hand, usually on the left side.
- A constricting sensation in the throat.
- The discomfort can radiate into both arms, the jaw, teeth, ears, stomach and in rare cases between the shoulder blades.
Unstable angina is associated with the same symptoms at rest.
In some cases the fatty deposits that restrict blood flow can rupture.
Blood then clots around the rupture, and the clot may be large enough to block the artery and seal off the blood supply. This may cause unstable angina or a heart attack.
How does a doctor diagnose angina?
Diagnosis is based on:
- the presence of typical symptoms
- medical history
- whether glyceryl trinitrate relieves the pain.
An electrocardiogram (ECG) is a test that measures the electrical activity of the heart and can help diagnosis if done during an episode of pain.
In addition, you may be given an ECG exercise test on a treadmill or exercise bike (a stress test) to determine if the heart muscle is the source of the pain. This test is usually done by a specialist in a hospital.