Angina is usually caused by coronary heart disease (CHD), a condition where the arteries supplying your heart narrow and harden with a build-up of fatty deposits called plaques (known as atherosclerosis).
Anything that causes the arteries to narrow increases the risk of angina; so, high blood pressure, smoking, ageing, raised cholesterol, diabetes, lack of exercise and family history of CHD, are all risk factors. If an artery becomes completely blocked, part of the heart muscle may be starved of oxygen and become damaged, resulting in a heart attack.
Less common causes of angina include variant angina, where the artery goes into spasm, and cardiac syndrome X, where the arteries don’t appear narrowed, but symptoms persist.
Apart from chest pain and discomfort spreading to the arms, neck, jaw and back, angina can feel like indigestion. Other symptoms include, feeling sick, unusually tired, dizzy, restless and breathless.
Symptoms usually start on exertion, during periods of stress, in cold weather or after a meal. During these times when your heart muscle has to work harder the demand for blood is increased, the narrowed arteries struggle to keep up. The heart then receives too little oxygen, resulting in pain.
Unlike the chest pain that accompanies a heart attack, angina pain usually eases off with rest and glyceryl trinitrate (GTN) spray, which works by relaxing blood vessels. However, sometimes if you have angina you can have a heart attack, so if the pain doesn't go after five minutes you will need to take another GTN dose. If the symptoms still don't ease after another five minutes then it’s time to call 999.
Your doctor may diagnose angina from your symptoms, but they may also carry out some tests for other markers of CHD including: blood pressure; blood tests for glucose and cholesterol levels; an electrocardiogram (ECG), which records the electrical activity of your heart; and a chest X-ray.
Further investigations include: an exercise tolerance test, where your heart is measured by an electro cardiogram whilst you exercise on a treadmill; a nuclear myocardial perfusion scan (MPS),where a radioactive substance is injected into the blood to track it moving through blood vessels and into the heart; and a heart CT scan.
A coronary angiography, which injects a special dye in your arteries, will reveal if your coronary arteries are narrowed and if so how severe any blockages are.
Who gets angina?
The risk of angina increases after age 45 in men and 55 in women. Angina affects one in 12 men and one in 30 women between the ages of 55 and 64. This rises to one in every seven men and one in 12 women over 65.
There are two types of angina, stable and unstable.
With stable angina, you’re more likely to have regular symptoms brought on by a predictable trigger, such as exercise. One in every 100 people with stable angina will have a fatal heart attack or stroke, and as many as one in 40 will have a non-fatal heart attack or stroke.
Treatment options for stable angina include lifestyle changes, including: quitting smoking, losing weight and taking more exercise, as well as medication. Glyceryl trinitrate (nitrates) tablets and spray can provide immediate relief of symptoms and act as a preventative if used before exercising. Long-acting nitrates are available as patches or creams.
Beta-blockers to reduce blood pressure and calcium channel blockers, to relax blood vessels, are also used to reduce the frequency of angina attacks.
Unstable angina can develop without any triggers and continue despite resting. You may need to be admitted to hospital urgently or referred to cardiologist for angiography (and possible surgery).