A coronary angiogram is also known as an angiogram or cardiac catheterisation. This test looks at the main arteries (coronary arteries), which supply the heart with blood and oxygen. It will show your consultant the exact location and seriousness of any narrowed areas in your coronary arteries.

This test gives us a better understanding of how well your heart is working, which will help us decide what the best treatment is for you.  

An angiogram is a relatively safe test, as serious complications are quite rare. The risk of a serious complication is less than one in a thousand. All medical procedures carry some risk, but it's important to remember that we would not recommend any procedure if we did not believe the benefits outweigh any risks.

Your general health and condition of your heart will affect some of the risks. Your doctor will discuss with you the risks specific to your condition in more detail.

What to expect

The test usually takes 30 minutes to an hour and will be done in a cardiac catheterisation laboratory (cath lab). We will inject a local anaesthetic into your groin or wrist so you should not feel any pain.

If you feel anxious about this, let us know and you can have a sedative to help you relax.

The procedure

  1. We'll make a small cut in your groin or wrist then insert the catheter into the blood vessel. We will direct it towards the heart, using moving X-ray images as a guide.
  2. Once the catheter reaches the heart, we inject a special dye into it. The dye shows up any narrowed areas or blockages in your arteries on the X-ray. The dye injection may cause you to feel a hot flushing sensation for a few seconds. You may feel an occasional missed or extra heart beat, but it should not cause you to feel any pain.
  3. After we've taken some X-ray images, your cardiologist may ask you to take a few deep breaths and hold your breath. If you sometimes get angina, you may experience chest pain during the test. But the pain should not be worse than normal.
  4. During the test, we'll use a heart monitor to check your heart rate and rhythm. Please let either the doctor or nurse know if you have new pain or other symptoms, such as shortness of breath.

When we have finished taking the X-ray images, we will remove the catheter and apply firm pressure. This is to stop any bleeding in your groin or wrist. 

Sometimes we use a small plug, called an angioseal, to stop any bleeding and speed up your recovery.

Immediately after your angiogram

Most patients are able to go home on the day of the test. If not, you should be able to go home the following morning. Before you go home, we will ask you to walk up and down the ward several times. This is to make sure that the small wound in your groin has healed enough for you to go home. Your nurse will check this.

The dressing (bandage) will usually be removed before you go home. You may have some bruising and a little tenderness in this area. Remember to keep the wound clean and dry.

You will need someone to drive you home. You should not drive for 24 hours after the procedure. If you have had a heart attack, you should not drive for at least a month after the procedure.

If you have any questions once you are at home, please contact the ward that you were admitted to. You will be given contact details before you are discharged.

But if you feel you need treatment urgently, contact your GP or go to the nearest accident and emergency (A&E) department.

You can find out more information about medications and angiograms by clicking on the 'Information' tab.

Heart failure means the heart has become less effective in pumping blood around the body.

The term 'heart problems' incorporate a number of specific conditions, such as coronary artery disease, angina and heart attacks. 

Angina is the term given to a cramp-like pain or heaviness felt mainly in the chest and left arm. It occurs when not enough blood is reaching the heart. 

Coronary artery disease is also known as 'ischaemic heart disease' and occurs when a fatty substance called 'atheroma' develops on the inside of an artery.

Angiogram alternatives

Angiograms are currently the best way of finding out exactly where the narrowed areas in the coronary arteries are. It is an essential test if you are going to have surgical or catheter treatment for your coronary artery disease.

There are other tests like thallium scans and exercise tests for coronary artery disease. But these tests show where and how severe the narrowed areas are.

After your angiogram

We recommend drinking one and a half litres of fluid during the first few hours after your angiogram. This helps your body to get rid of the dye used during the procedure. You should also rest for the first day after your angiogram. If you were working before you were admitted, you should be able to return to work 24 hours after your angiogram.

You must not drive for 24 hours after your angiogram. You will need someone to take you home after you have been discharged.

Try to avoid lifting objects and doing any activities that will make you tired during your first week. You may experience some pain in your wrist or groin (where the catheter was inserted) for a few days after the angiogram. This is common and the pain will improve.

Depending on the results of your angiogram, we'll be able to give you more information about what you can and can't do. If you have any questions about this, feel free to ask your doctor or nurse before you go home.

If your follow-up appointment is planned at Harefield Hospital, we will send your appointment details by post. Your GP can arrange for you to be seen earlier if they feel it is necessary.


You can remove the dressing from your wrist or groin the morning after your procedure. Your nurse will check the wound before you leave the hospital.

Check your wound for any signs of excessive bruising, inflammation or swelling for a few days following the procedure. If you see any of these or have any concerns, contact us. We may ask you to return to the ward so we can look at your wound.

Caring for your wound

Looking after your wound is really important. You can do this by:

  • keeping your wound as clean and dry as possible
  • avoiding putting perfume, cream or talcum powder on, or around, the wound for at least a week
  • not taking a bath for at least 24 hours after your procedure. This may slow the healing process, or cause the wound to bleed. It is fine to take a shower
  • sitting down and pressing on the wound firmly for 10 minutes if it starts to bleed. Once the bleeding has stopped, you should apply a plaster to it for 24 hours. If it continues to bleed, call your GP or go to your nearest accident and emergency (A&E) department - Harefield Hospital does not have an A&E department.

Angina (chest pain)

It is possible that you may still experience some angina after your procedure. If you have any chest pain, stop what you're doing and rest.

If you use GTN spray, or GTN tablets and the pain persists even if you have rested, take one spray or tablet. If you can still feel the pain after five minutes, repeat this and wait another five minutes.

If you can still feel the pain after 15 minutes, you should dial 999 immediately.

If you experience a gradual return of your chest pain in the weeks after the procedure, please see your GP.

Your angiogram results

Your cardiologist will look at the angiogram and may suggest you:

  • continue your current medication
  • have treatment to widen your coronary artery using coronary angioplasty and/or a stent
  • have surgery to re-direct blood around the blocked arteries, by using another vein or artery, known as a coronary artery bypass graft 

Female patients

If you think you may be pregnant, please let us know beforehand. If you have not had a period in the 10 days before the procedure, we will need to carry out a pregnancy test. This is because the test uses X-rays that may be harmful to an unborn baby.

Eating and drinking

Please follow the instructions in your confirmation letter about eating and drinking before the test. You may drink water until it is time for your test.

What to bring to your appointment

Before you come for your angiogram, please do not shave or remove hair from your chest, arms, legs or groin before coming into hospital. If this needs to be done, we'll do it in hospital just before your angiogram.

It's also important to have a thorough shower or bath, the night before you come into hospital. Pay close attention to washing under any skin folds, such as under the breasts, the groin and genital area.

Contact the ward before you leave home to make sure a bed is available. You should also make arrangements for someone to take you home after the test, as you will not be able to drive for the first 24 hours.

Remember to bring:

  • all your current medication
  • a dressing gown
  • comfortable, well-fitting slippers with a good grip



If you take warfarin, you may need to stop before the test. Your anticoagulant clinic doctor or hospital consultant will discuss this with you. If you have an artificial heart valve or have had a stroke, warfarin should only be stopped on the night before you have the test.


You must stop taking Metformin 48 hours before you have the test. You can then start taking it again 48 hours after the test. If you have any questions about this, ask your consultant. Take all your usual morning medication (except warfarin) as you would normally. This test can take up to an hour, so you may prefer to leave out any water tablets until after the test.

Please bring all your medication (including warfarin and Metformin) with you to hospital.

Contact us

If you have any questions, contact us:

Harefield hospital

Contact the following at Harefield hospital  if you have any questions: 

  • Cardiac rehabilitation dept (Mon-Fri, 8am-4pm) 01895 828 944
  • Cardiology nurse consultant 01895 828 677 (Mon-Fri, 8am-5.30pm. You can leave a message and your call will be answered as soon as possible)
  • ACCU – Oak ward (24 hours) 01895 828 648/667
  • ACCU – Acorn ward (24 hours) 01895 828 723
  • Cherry Tree day case unit (Mon-Fri, 7.15am-8pm) 01895 828 656 Switchboard 01895 823 737

Royal Brompton hospital

Contact the following at Royal Brompton hospital if you have any questions:

  • Pre-assessment nurse specialists 020 7349 7753 (Monday-Friday, 10am-4pm)
  • York Ward 020 7351 8592 (24 hours)
  • Paul Wood Ward 020 7351 8598 (24 hours)
  • Switchboard 020 7352 8121
  • Cardiac bookings team (bleep via switchboard) 1195