Coronary angiogram

About an angiogram

An angiogram is a procedure that can help to diagnose heart conditions. It involves putting a long, thin, flexible tube called a catheter into a blood vessel in your groin or wrist. The catheter is then guided to your heart and a special dye (contrast agent) is injected through the catheter, so that X-ray images show your heart and coronary arteries more clearly.

An angiogram can help to find out if the blood vessels to and from your heart are narrowed or blocked, and if so, where and how badly they are affected. It can also be used to see how well your heart is pumping blood.

An angiogram can be done on adults, children and newborn babies.

Preparing for an angiogram

Your doctor will explain how to prepare for your procedure. For example, you may be asked to stop taking anticoagulant medicines (such as warfarin) about two days before the angiogram.

You will be asked not to eat or drink anything for a few hours before you have the angiogram.

The angiogram is usually done as a day case under local anaesthesia. This completely blocks pain from where the catheter enters your blood vessel (in your groin or wrist) and you will stay awake during the procedure. You may be offered a sedative during the procedure. This relieves anxiety and will help you to relax.

Your doctor will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

Special considerations – pregnancy and breastfeeding

If you’re pregnant, or think you might be, tell your doctor before your appointment. Your doctor will discuss with you whether having an angiogram while you’re pregnant is appropriate.

If you’re breastfeeding, tell your doctor before your appointment. There is a small risk that the contrast agent and any other medicines you have during your angiogram could get into your breast milk. This could affect your baby. Your doctor will discuss with you whether you need to plan not to breastfeed for a short time after your angiogram, or whether there is an alternative procedure you can have.

See our frequently asked questions for more information.

What happens during an angiogram?

An angiogram usually takes about 30 minutes.

A cardiologist (a doctor who specialises in conditions affecting the heart), cardiac physiologist (a health professional trained to perform cardiac investigations) and a radiographer (a health professional trained to perform imaging procedures) will carry out the test. A nurse will usually stay with you throughout the procedure.

Angiograms are carried out in special rooms that are designed to contain all the equipment that is needed for the procedure. You will be taken into one of these rooms, which are often located in the hospital’s X-ray department. You will be asked to change into a hospital gown.

You will be connected to a heart monitor that records your heart rate and rhythm during the procedure. Tell your nurse if at any time you feel unwell or experience any discomfort.

You will lie on a table and an X-ray machine will be positioned above your chest. Your cardiologist will inject local anaesthetic into your skin where the catheter will enter your blood vessel – this is called the entry site.

Your doctor will thread the catheter into the artery in your groin or your wrist, and move it up through the vessel to the opening of your coronary arteries. Your healthcare team will take X-ray images of your heart and your doctor will look at the images on a monitor to carefully guide the catheter into your heart. When the catheter has reached the right place, your doctor will inject a special dye into the catheter. More X-ray images will be taken as the dye flows through your blood vessels and heart. Your doctor will look at these on the monitor to see if there is any narrowing in your blood vessels.

You won't feel the catheter in your artery, but when the dye is injected, you may have a warm feeling.

You will have the catheter removed when the test is complete. Your nurse will either press firmly over the entry site for up to 20 minutes or insert a small collagen plug called an arteriotomy closure device (commonly an angioseal type) to help seal the blood vessel. The plug usually dissolves in 60 to 90 days.

If the catheter is inserted into your wrist, you will be given a tight band to wear around your wrist for two to three hours after your angiogram.

What to expect afterwards

If your angiogram was performed from the groin, you will need to lie flat for a few hours to allow the blood vessel to seal properly. Your nurse will regularly check your blood pressure, heart rate and the catheter entry site. If it was done from the wrist, you should be well enough to get up an hour or so after the procedure.

You will usually be able to go home when you feel ready. You will need to arrange for someone to drive you home.

The cardiologist performing the angiogram will usually discuss the results with you before you go home. Alternatively, your results may be sent in a report to the doctor who recommended your angiogram, who will arrange to see you to discuss the results. Other findings may be discussed before you leave the hospital. If you were given the sedative during your procedure, it's a good idea to have someone with you if the results are being discussed immediately after the procedure, as you may not remember the details clearly.

Recovering from an angiogram

Take it easy for the rest of the day and don't do any vigorous walking or heavy lifting for the first few days after you have an angiogram.

The dressing covering the entry site on your skin can be removed and changed if needed after 24 hours. You can have a shower and carefully pat dry your wound afterwards.

Sedation temporarily affects your co-ordination and reasoning skills, so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours afterwards. If you're in any doubt about driving, contact your motor insurer so that you're aware of their recommendations and always follow your doctor's advice.

What are the risks?

Angiograms are commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible side-effects and the risk of complications.


Side-effects are the unwanted, but mostly temporary effects you may get after having the procedure. Side-effects of an angiogram may include:

  • mild chest pains or a fluttery heartbeat during an angiogram
  • bruising and/or swelling at the catheter entry site


Complications are when problems occur during or after the procedure. Most people are not affected. The possible complications of an angiogram include bleeding during or very soon after the procedure, infection or an unexpected reaction to the anaesthetic.

Other less common complications of an angiogram are listed below.

  • Allergic reaction to the dye. This happens in around one in 100 people having an angiogram, but medicines are available to help treat this.
  • Irregular heartbeat (arrhythmia) – this is caused by the catheters within the heart or the dye injection, and will settle by the end of the procedure.
  • Build-up of blood under your skin (haematoma) – this can happen if your blood vessel is damaged and you may require surgery to drain the area.
  • Damage to the blood vessels leading to your heart – you will require urgent surgery to repair the damage.
  • Heart attack or stroke – very rarely, the tip of the catheter can dislodge a blood clot or fatty plaque from the wall of your blood vessel. There is a risk that these may block the blood supply to your heart or brain and trigger a heart attack or stroke. This happens in about five in 10,000 people who have an angiogram.
  • Fatality. This is very rare and happens in less than one in 10,000 people during or after an angiogram. The risk is increased in people who already have other conditions, such as problems with their lungs or kidneys.

As with every procedure, there are some risks associated with having an angiogram. Ask your doctor to explain how these risks apply to you.

Is the angiogram procedure the same in children?


The procedure is exactly the same, but it's often done under general anaesthesia. The staff at the hospital will take other steps to help keep your child safe during the procedure.


An angiogram is usually done under general anaesthesia in young children because it's important for them to remain still during the procedure and young children may get scared by the test. This means your child will be asleep during the angiogram.

It’s unlikely that you will be allowed to stay with your child during an angiogram because there is a risk of you being exposed to radiation and to help keep the environment sterile. You will be able to be with your child when he or she wakes up from the anaesthetic.

The staff carrying out your child’s angiogram will adjust the radiation doses to your child’s size because children are more sensitive to radiation. The type of contrast agent used and the catheters to deliver the dye will also be appropriate for your child.

Your child’s doctor will ask you about your child’s health and medical history. You must tell your child’s doctor if your child is taking any medicines before the procedure, or if he or she has any medical conditions, such as kidney disease or diabetes. Your child’s doctor will explain the procedure to you, so you can ask him or her any questions you have about it. He or she will ask you to sign a consent form for your child’s procedure to go ahead.

Your child will be asked to follow fasting instructions. This means not eating or drinking, typically for about six hours beforehand. However, it's important to follow your child’s doctor's advice. Often, the procedure is planned for the morning, so that your child will only have to miss breakfast.

Although there are risks from having an angiogram, this procedure may be able to diagnose or treat your child’s heart condition more quickly and safely. This could mean that he or she won’t need further procedures, such as surgery.

If you have any questions about your child having an angiogram, talk to his or her doctor. There may be alternative procedures available.

What type of dye is used during an angiogram?


The dye is a colourless liquid called a contrast agent and usually contains iodine. The dye shows up as a black shadow on X-ray images.


The heart and blood vessels are difficult to see on X-ray images. Contrast agents (also known as contrast media or dye) are often used during the examination to highlight heart muscles and blood vessels, and make them easier to see.

The contrast dye used during an angiogram is usually iodine-based. Iodine-based contrast dyes are clear liquids and usually excreted harmlessly in the urine or faeces. However, there is a small risk of having an allergic reaction, so it's important to tell your doctor if you have any type of allergy, particularly to seafood (which contains iodine). If you have skin allergies or asthma, you may be more likely to be allergic to the contrast agent.

As the contrast dye reaches your heart, you may feel a warm, flushing sensation or a fluttery heartbeat. You may also get a metallic taste in your mouth, feel light-headed, sick or itchy. Usually, these symptoms are mild and disappear quickly. However, it's a good idea to tell your nurse or doctor if you experience any of them.

Contrast agents can cause a problem if you have poor kidney function. Please remind your cardiologist if you have kidney problems so that a different contrast agent can be used. Contrast agents can also cause kidney problems in people taking metformin, a common treatment for diabetes. Please let your cardiologist know if you take metformin.

Why do I need to stop taking aspirin before an angiogram?


Aspirin can increase your risk of bleeding during and after an angiogram.


Aspirin is an anti-inflammatory painkiller, which is widely used for pain relief and to reduce inflammation and temperature. It thins your blood so that it can flow better through narrowed blood vessels. However, this also means that your blood doesn't clot easily when you bleed.

Your doctor may give you a low dose of aspirin to help reduce your risk of a heart attack and stroke. However, you may be asked to stop taking aspirin five days before your angiogram to reduce your risk of bleeding during and immediately after the procedure.

If you're taking anticoagulant medicines, such as warfarin, you may be asked to stop these too.

Your doctor will explain how to prepare for your angiogram and it's important that you follow his or her advice.

Can I have an angiogram if I am pregnant or breastfeeding?


This will depend on many factors, such as how serious your heart condition is, the risks the procedure involves for you and your baby, and what alternative procedures are available to make a diagnosis.

If you’re pregnant, or think you might be, or you’re breastfeeding, tell your doctor before your appointment.


There are risks from complications of an angiogram that you may want to consider before you have the procedure. The risks vary from person to person, but having an angiogram has a risk of complications for five in 1,000 people having this procedure. However, if you’re pregnant, there are additional risks because of the effect the procedure could have on your unborn baby.

An angiogram might not be suitable for you to have when you’re pregnant. One reason is that an angiogram involves taking X-ray images of your heart. X-ray images are also used to track the progress of the catheter in your arteries leading to your heart. Your unborn baby is at risk of being exposed to the radiation. It may be possible to protect your abdomen (tummy) using a lead shield, which will stop any radiation reaching your baby.

The second is that a contrast agent will be used to highlight your coronary arteries. It’s possible that this could cross the placenta and affect your baby. Different types of contrast agent may be safer for you and your baby.

The benefits of getting the right diagnosis and treatment for your heart condition while you’re pregnant may outweigh the risks of the procedure affecting you or your baby.

If you’re breastfeeding, it’s possible that the contrast agent, or any other medicines you’re given during your angiogram, could get into your breast milk. You may need to plan to stop breastfeeding for a short time after your angiogram. Your doctor will be able to advise you about this.

If you have any concerns about having an angiogram when you’re pregnant or breastfeeding, talk to your doctor.