Coronary artery spasm

What is a coronary artery spasm?

The spasm slows or stops blood flowing through the artery and so reduces the blood supply to the heart muscle. Coronary artery spasm is sometimes called variant angina or Prinzmetal's angina. Angina is a medical term for chest pain.

Symptoms of a coronary artery spasm

Coronary artery spasm may occur without any symptoms. The most common symptom is heart chest pain (angina). If the coronary artery spasm is severe and lasts long enough then it may cause a heart attack (myocardial infarction).

Chest pain (angina)

With angina, the pain is usually described as:

• Severe pain that can be felt under the breast bone (sternum) or on the left side of the chest.

• A feeling of crushing, pressure, squeezing or tightness.

• A pain that spreads to the neck, jaw, shoulder or arm. It may feel like it's in the back.

The chest pain caused by coronary artery spasm often occurs at rest and commonly doesn't occur during exercise. This is very different from angina due to fatty patches or plaques (atheroma), when the pain is usually triggered by exercise and goes away when you rest.

The chest pain may occur at the same time each day and most often occurs during the night and early morning. The pain can be very variable but usually lasts between 5 and 30 minutes. It can occasionally spread to the back. The pain does not improve with change of position, unlike pericarditis, which is sometimes relieved by leaning forward.

Coronary artery spasm may also cause shortness of breath. A severe episode of coronary artery spasm may cause a loss of consciousness.

Causes of a coronary artery spasm

Coronary artery spasm often occurs in coronary arteries that have not already become blocked with fatty patches or plaques (atheroma). However, coronary artery spasm can also occur in coronary arteries that are already partially blocked with atheroma.

Coronary artery spasm may occur without any obvious cause. At other times the spasm may be triggered by various factors such as:

• Emotional stress.

• Alcohol.

• Exposure to cold.

• Stimulant drugs (such as amphetamines and cocaine).

What else could it be?

Coronary artery spasm is sometimes mistaken for other heart-related (cardiac) causes of chest pain such as pericarditis, a heart attack and cardiomyopathy. Non-cardiac causes of chest or upper tummy pain may need to be ruled out such as gallbladder disease and stomach ulcers.

How common is a coronary artery spasm?

About 1 person in every 50 with angina has coronary artery spasm. Coronary artery spasm is more common in males and those aged between 40 and 70 years.

Coronary artery spasm is more common in people who:

• Smoke.

• Have high blood pressure.

• Have high blood cholesterol level.

However, coronary artery spasm may occur without any risk factors for heart disease such as smoking, diabetes, high blood pressure and high cholesterol.

Diagnosing a coronary artery spasm

If you are thought to have heart chest pain (angina), you will usually be referred to see a specialist for investigations.

The initial investigations will include:

• Blood tests.

• A 'heart tracing' (electrocardiogram, or ECG).

• An ultrasound heart scan (echocardiogram, or 'echo').

• A coronary angiography.

Other investigations may also be used, including:

• A myocardial perfusion scan.

• A radionuclide (isotope) scan.

• A magnetic resonance imaging (MRI) scan.

The coronary angiogram may be normal if there is no blockage of the coronary arteries caused by fatty patches or plaques (atheroma). However, coronary artery spasm can be triggered by injecting a chemical into one of your veins. This is called a provocation test.

The chemical is otherwise safe and the coronary angiogram may then show temporary narrowing of the coronary arteries in people with coronary artery spasm.

Coronary artery spasm treatment

The aim of treatment is to control chest pain and to prevent a heart attack (myocardial infarction). The most important aspects of treatment are to avoid any known triggers for coronary artery spasm and to reduce the risk of heart disease. Reducing the risk of heart disease includes:

• Lifestyle advice to stop smoking, eat a healthy diet, have regular exercise and reduce body weight if overweight.

• Medicines may be needed, such as to control high blood pressure or a high cholesterol level.

See the separate leaflet called Cardiovascular disease (Atheroma).

Glyceryl trinitrate (GTN) can be used to relieve an episode of chest pain. Your healthcare provider may prescribe other medicines to prevent chest pain. You may also need a type of medicine called a calcium-channel blocker or a long-acting nitrate. Beta-blockers should be avoided because they may make this condition worse.

You will need to be referred to a heart specialist for further investigations and treatment. Further treatments may include coronary angioplasty if you also have coronary artery blockage caused by fatty patches or plaques (atheroma).

An implantable cardioverter defibrillator may be needed if you are at risk of life-threatening abnormal heart rhythms caused by coronary artery spasm. See the separate leaflet called Abnormal heart rhythms (Arrhythmias) for more details.

Complications of a coronary artery spasm

Coronary artery spasm may cause an abnormal heart rhythm (arrhythmia), which may be life-threatening. Severe and prolonged coronary artery spasm may cause a heart attack (myocardial infarction).

What is the outcome?

Coronary artery spasm is a long-term condition. However, treatment most often helps to control symptoms. The outcome (prognosis) for people with coronary artery spasm is generally good if they follow treatment recommendations and avoid certain triggers.

The outcome is not as good in people who also have blockage of the coronary arteries caused by fatty patches or plaques (atheroma).