Dr Simon Kennon MB ChB, FRCP, MD Consultant Cardiologist

Diagnostic Coronary Angiogram

This is the gold standard test to image the arteries supplying blood to the heart – the coronary arteries. X-rays are taken while contrast dye is injected into the arteries. The contrast outlines the arteries demonstrating any narrowing or blockages. This test is required to determine the extent and severity of coronary artery disease and is required before any stenting procedure or bypass operation can be undertaken. is a procedure that uses X-ray imaging to see your heart's blood vessels. It does this in conjunction with a catheter (a long, flexible tube), which is fed up to the heart and coronary arteries, using X-ray images as a guide. A special type of dye is then injected into the catheter. This enables the arteries and their smaller branches to show up on an X-ray, highlighting any blood vessels that are narrowed or blocked.

What to expect

this test is undertaken in a cardiac catheter laboratory, a room specifically designed for this test. You are asked to lie on a mobile, cushioned table. Under local anaesthetic, a narrow (around 2mm) but long (150cm) flexible tube is passed into an artery in your right wrist or into the artery at the top of the right leg. It is then passed up to your heart where the contrast dye can be injected directly into the arteries supplying blood to the heart. When the contrast is injected, x-rays are taken and the contrast shows up on x-rays – outlining the coronary arteries and demonstrating any narrowings or blockages. The test takes about 15 minutes. If appropriate a stenting procedure can be undertaken at the same sitting.


This is an invasive test which involves a risk of less than 1% of heart attack, stroke and death. It also involves a small amount of radiation. Allergic reaction to the dye occurs rarely and is treatable. The contrast dye can effect kidney function but the risk of this is reduced by prehydration (as above). You should feel free to ask about these risks so that you are sure the benefits of the test outweigh the risks.