Coronary angiography

The coronary arteries supply your heart muscle with vital blood and oxygen so that your heart can pump blood around the body. The results of the angiography (which will give information on any narrowing in the coronary arteries) will help your doctor decide what treatments, if any, are best for you.

You will usually be seen at a pre-admission clinic some days or weeks beforehand. This allows baseline tests such as blood tests, an electrocardiogram (ECG), and a chest X-ray (if needed) to be done.

Make sure you know what food and drink you can have the night before and on the day of the angiography.

Also double check what medications to take, and if you need to withhold any for the procedure. Make sure you bring all your medications with you into hospital.

When having a coronary angiography, you  will usually be admitted to hospital for the day. If you go on to have a procedure such as angioplasty, you may need to stay in hospital overnight.

• The doctor or nurse will explain the procedure and any risks, and will answer any questions.
• They will ask about your medical history and note your allergies and medications.
• You may be given a sedative tablet to help you relax, but you'll still be able to follow the doctor's instructions.

Coronary angiography is done in a cardiac catheterisation laboratory, usually called a cath lab. You will be taken there from the ward on a movable bed.

Once you are in the laboratory you will be moved onto an examination table. You will be lying directly under an X-ray camera through which the angiography procedure can be viewed. The procedure takes about 30 minutes. It will be longer if anything else is done at the same time.

To access the coronary arteries, a long thin flexible plastic tube called a catheter is inserted into one of your arteries in your wrist or groin. Once the best option is decided, the area is cleaned and covered with sterile sheets. The doctor will inject local anaesthetic into this area. When the skin is numb, an introducing sheath (narrow tube) is inserted into your artery. A thin, flexible plastic tube called a catheter is then threaded through the sheath.

The catheter is guided through the artery until it reaches the part of the aorta, immediately outside the heart, where the coronary arteries begin. This should not cause any discomfort. The catheter's movement is monitored by x-rays which your doctor can see on a television screen. You may be able to watch this too if you are interested.

The coronary arteries do not show up on normal x-rays, so a special contrast fluid (dye) is used. Once the catheter is in place, the contrast fluid is injected through the catheter to highlight the blood in the coronary arteries. This will show any narrowings.

Sometimes other tests or procedures are done at the same time such as:

• measuring the blood pressure within your heart chambers
• checking the functioning of your heart valves and how well your heart is pumping
• angioplasty to place a stent in one or more of the coronary arteries that are narrowed.

Here is a short video of what to expect when you have a coronary angiography produced by Waikato hospital. You can skip the first minute of the video if you're not watching from the Waikato area as the first minute explains navigation within Waikato hospital. 

Video: Coronary Angiography procedure

This video may take a few moments to load.

(Health New Zealand | Te Whatu Ora Waikato, 2018)

Most people find having an angiogram is easier than they expect. Any pain or discomfort you feel will be closely monitored by the team looking after you throughout the procedure. Common feelings include:

• slight pressure as the catheter is inserted, but not when it's inside your blood vessels
• an occasional missed heartbeat – your heart rate and rhythm will be closely monitored
• wanting to pass urine and feeling flushed as the contrast fluid is given
• mild chest pain – if this happens, tell the doctor or nurse.

Very rarely, an allergic reaction to the X-ray contrast fluid can happen, so it's important to know if you have had a previous reaction. If you develop itching, a rash or welts, medicines are given to stop the reaction immediately.

Pressure will be applied to the area (wrist or groin) for up to 20 minutes to stop any bleeding. It's very important that you lie still during this time to prevent bleeding. If the catheter was inserted in your groin, you will need to lie flat for several hours. If the catheter was inserted into your wrist, you will be able to sit up and walk soon after, with help from your nurse.

When you return to the ward the nursing staff will regularly check the catheter insertion site, your blood pressure, pulse and circulation of either your lower leg or arm, depending on where the insertion site was. They will also encourage you to drink plenty of water to help flush the contrast dye out of your kidneys and body.

It is most important to follow the nurse's instructions. They will let you know when it is safe to sit up and slowly move around.

• If you feel any bleeding, pain, dizziness, sweating or a warm, wet feeling around the catheter insertion site, call the nurse immediately.
• If you experience discomfort at the site, inform the nurse and you will be given pain relief.
• It's normal to have some bruising around the site and for it to be slightly tender.
• You may feel a small lump where the sheath was inserted. This should disappear over the next few weeks.

Before going home, a nurse will teach you how to check the site for swelling or bleeding and will explain what to do if this does happen. You will need someone to pick you up. Once you go home, you can eat and drink normally. You should be able to resume normal activities within a day or two of the procedure. However, don't do any heavy lifting or straining for about a week to prevent bleeding or bruising from the insertion site.

If the angiogram shows a narrowing that can be treated immediately, your cardiologist may decide to go on to perform an angioplasty (procedure to widen a narrow artery). In most cases this will include inserting one or more stents.

Alternatively, an angioplasty and stenting might be scheduled for a later date, or coronary artery bypass graft surgery may be recommended. Your cardiologist will also prescribe appropriate medicines for you to take.

A letter will be sent to your healthcare provider, giving the results of your angiogram.