Coronary angiography is a special X-ray of the heart (coronary) arteries. It is mainly used if you have angina, to assess the extent and severity of any narrowings of the coronary arteries.

With coronary angiography, dye is injected down the coronary arteries. The arteries and their smaller branches then show up clearly on an X-ray ‘like a road map’. Dye is injected into the coronary arteries by using a catheter. (A catheter is a thin, flexible, hollow tube.)

How is coronary angiography done?

Coronary angiography is an invasive procedure performed under local anaesthetic and often mild sedation. A thin, flexible tube (a catheter) is inserted through a small cut in the skin into an arterial blood vessel in the groin or arm. The catheter is then slowly advanced up the blood vessel towards the heart. Low-dose X-rays are used to monitor the progress of the catheter tip which is gently manipulated into the correct position just inside a main coronary artery.

Contrast dye is then injected down the catheter into the artery and a cine Xray film is taken as the dye is injected and the recorded picture is called an angiogram. The angiogram shows the vessels filling with blood and the sites of any narrowing can be seen. The tip of the catheter is then put into the other main coronary artery and the test is repeated. The procedure is completed when all the coronary arteries and branches have been clearly visualised.

The procedure is not painful. The initial puncture site is numbed by the local anaesthetic and you cannot feel the catheter inside the blood vessels. You may feel an occasional ‘missed’ or ‘extra’ heartbeat during the procedure. This is normal and of little concern. During the procedure you may also experience a hot flush sensation when dye is injected in the main pumping chamber of the heart. This is very transient and is very rarely uncomfortable.

When the test is over, the catheter is gently pulled out. If it was inserted through a small cut in the skin in the wrist then it is controlled by a haemostatic band that is slowly released over the next few hours. If it was inserted through a wide needle in your groin then a specialist haemostatic collage device is inserted to stop bleeding or a nurse will press over the site of insertion for about 10 minutes to prevent any bleeding.

Coronary Angiography is a day-case procedure and usually takes about 30 minutes to complete the test.

Are there any risks or side-effects?

Most of the side-effects are minor and may include:

• Bruising under the skin at the catheter entry site is the most common side effect and may last up to a week post procedure. This is not serious, but it may be sore for a few days.
• The small wound where the catheter is inserted sometimes becomes infected. Tell your GP if the wound becomes red and tender. A short course of antibiotics will usually deal with this if it occurs.
• Rarely, some people have an allergic reaction to the dye. If this occurs you should seek medical attention.

Serious complications are rare quoted at 1 in 1000 and include stroke or a heart attack during the procedure. The risk of serious complications is small and is mainly in people who already have serious heart disease. As a consequence of serious complications, some people have very rarely died during this procedure. Therefore coronary angiography should only be recommended if the benefits of the test outweigh the small risk.