Coronary angiogram

What is an angiogram?

An angiogram (a type of cardiac catheterisation) is a heart test that looks at the blood supply of your heart. It helps the doctor spot any narrowings inside the coronary arteries.

A special dye is injected into an artery in your arm or leg, which travels to your coronary arteries. When it gets there, an X-ray photograph is taken of the artery to look for any narrowings of the coronary arteries. This may be a sign of coronary heart disease.

Depending on your results, the procedure can help your doctor decide what treatment you might need. 

What happens during an angiogram?

The test is done in a cardiac catheter laboratory or ‘cath lab’. You can expect the test to last around half an hour, although it can sometimes take longer. You will need to lie flat for the procedure.

• You will be asked not to eat or drink anything for a few hours before your procedure. Please let the nurse know if you have diabetes so they can look after you.
• You’ll be given a local anaesthetic injection in the wrist or groin, which numbs the area. The doctor will make a small cut and the catheter (a thin, flexible tube) will then be pushed into an artery.
• The catheter will be directed through your blood vessels and up to your heart. The doctors will use X-ray to help guide them to the arteries.
• A special dye called contrast will then be passed through the catheter and a series of images will be taken. It is very common to feel a hot, flushing sensation as the dye enters your bloodstream, but this is completely normal and only lasts for a few seconds. The dye will show up any narrowed areas or blockages in the artery on the X-ray photos.
• You will be awake and able to talk to the medical team throughout your procedure. You’ll be attached to a heart monitor that records your heart rate and rhythm and you’ll have a probe measuring your oxygen levels on your finger. If you feel unwell or uncomfortable at any time, you should tell a member of the hospital staff.
• If you are feeling very anxious about having this test, you can ask for a mild sedative to help you relax.

What happens after an angiogram?

After the procedure, the catheter will be removed from the groin or wrist area, depending on which artery the doctor used. To stop the artery from bleeding, pressure will be applied to the groin or wrist and a special seal or pressure device will be applied. You will be able to sit in a chair almost straight away.

If the doctor prefers to apply a pressure pad to the cut, you will need to stay in hospital a bit longer, usually around 4 hours.

The nurses will check your blood pressure and pulse and keep an eye on your wound. It is important to drink plenty of fluid as this helps to flush the dye out of your system.

As long as you feel well, you should be able to go home the same day, although this may depend on the results. Your doctor will explain these to you before you leave.

The most common after-effect is bruising where the catheter was put in, which may feel tender and numb for a few days. You might feel tired, but you should be back to normal within a few days. If you are worried about any of the after-effects, contact your doctor.

Some people who have a coronary angiogram go on to have a treatment called coronary angioplasty.

What is a CT coronary angiogram?

CT stands for ‘computerised tomography’.

A CT coronary angiogram shows the blood flow through the coronary arteries. For this test the dye is injected into a small vein in your arm. This makes the test less invasive than a traditional angiogram. 

You will then lie on a bed which passes through a doughnut-shaped opening in a CT scanner to show detailed images of your heart. Some people feel a bit claustrophobic during this test, so let the team know if you feel nervous.

A CT coronary angiogram is generally not as reliable at detecting narrowings in small coronary arteries or in small branches as a traditional coronary angiogram. This means that coronary angiogram is still the ‘gold standard’ for diagnosing coronary heart disease.

What are the risks of having an angiogram?

An angiogram is a relatively safe, very common test. Serious complications are rare and your doctor will discuss these before you have it done.

Following an angiogram, some people may develop a collection of blood under the skin, which is called a haematoma. This can be uncomfortable and cause bruising, but it should go down after a few days. However, contact your doctor if you have any concerns.

A small amount of radiation is used during an angiogram. However, as this test checks the blood flow through the arteries of the heart, it is essential to have it done.