Cardiac syndrome X

What causes it?

Numerous theories exist: one explanation is that some people suffer an abnormal perception of pain; another is that a condition called microvascular angina is responsible. This is when the smaller arteries supplying the heart are narrowed but not outlined, or seen, with an angiogram.

Cardiac syndrome X occurs most often in young women.

What are the symptoms?

Patients with the syndrome experience angina-like chest pain.

With angina, the pain occurs as a result of narrowing of the coronary arteries that reduces blood flow to the heart and is often triggered by exercise.

In cardiac syndrome X, the pain may also be triggered by exercise, but when a treadmill or stress ECG test is performed to investigate the cause of the pain the result is positive. Similarly, when an angiogram - an x-ray dye test of the coronary arteries - is performed, no narrowing or hardening of the arteries is found.

It's generally thought that to diagnose cardiac syndrome X the following criteria need to be fulfilled:

• Angina chest pain
• Positive stress test
• Completely normal coronary angiogram

What's the treatment?

Treatment can be provided once other possible causes of the pain have been excluded - for example, indigestion, musculoskeletal pain and psychological problems.

Anti-anginal medicines, such as nitrates, beta-blockers and calcium-channel blockers, may be useful. These can relieve the symptoms of chest pain and lessen the frequency of painful episodes.

The outlook for patients with cardiac syndrome X is good. They're much less likely to have a heart attack than people with narrowing of the major coronary arteries.

But this doesn't mean they can afford to be complacent about their lifestyle. It's still important for patients to look after their heart and blood vessels by not smoking, eating healthily and keeping active within their capabilities.