Cardiac catheterisation and coronary angiography

How cardiac catheterisation and coronary angiography are performed

Cardiac catheterisation and coronary angiography will be carried out at a hospital or specialist heart centre.

The team responsible for your care will usually include a cardiologist (heart specialist), nurse, cardiac technician and a radiographer (a specialist in using imaging technology).

The procedure will usually be carried out in an X-ray room or a catheterisation laboratory.

Before having the procedure, you should tell your cardiologist if you have any allergies and if you are taking any medication, either for a heart problem or another medical condition.

If you are on blood-thinning medication, you will be told to stop this. This is likely to be 5-3 days prior to the procedure. You should not stop taking prescribed medication unless you are advised to do so.

Occasionally, you may also be asked not to eat or drink anything for 6 hours before the procedure.


The procedure will be carried out under local anaesthetic and you may also be given the option of having a sedative.

If you are sedated, you will feel sleepy and relaxed but remain awake and have enough awareness to respond to instructions.

For example, you may be asked to take a deep breath and hold it at certain points during the procedure.

Monitoring your heart

Throughout the procedure, you will be attached to an electrocardiogram (ECG) machine. An ECG records your heart's rhythms and electrical activity. A number of electrodes (small, metallic discs) are placed on your arms, legs and chest. The electrodes are connected to a machine that records the electrical signals of each heartbeat.

The procedure

Provided that you do not need to have a further follow-on procedure, such as a balloon angioplasty and stent (see below), cardiac catheterisation and coronary angiography should take about half an hour.

Below is a step-by-step guide to what you can expect during the procedure. The healthcare professionals who are with you will explain what is happening.

  • After entering the catheterisation laboratory, you will be asked to lie on a special table. If the catheter is being inserted into your groin, your groin may be shaved and will be cleansed with antiseptic fluid.
  • You will be covered with a sterile sheet and given an injection of local anaesthetic to numb the skin of your groin or arm, so the procedure should not be painful.
  • The catheter will be inserted through a fine tube called a sheath.
  • The catheter will be moved through your blood vessels and into your heart using X-ray guidance.
  • A small amount of special dye called contrast medium will be injected through the catheter, and the pressure in your heart will be measured.
  • As the dye is injected, you may feel a hot flushing sensation that passes quickly. You may experience a warm sensation in your groin that feels as if you have wet yourself. You may also have a metallic taste in your mouth. This is nothing to worry about, and you will be warned when to expect it.
  • You will not feel the catheter being guided through your blood vessels. However, you may be aware of the odd missed or extra heartbeat.
  • A series of X-ray images will be taken of your heart and the blood vessels around it. These are called angiograms and will be stored digitally (on a computer).
  • In certain circumstances – for example, if your arteries are blocked – your cardiologist may decide to carry out a balloon angioplasty and stent (an interventional procedure to widen blocked arteries). This will be carried out immediately and will add about an extra half hour to the procedure. This should usually have been discussed with you beforehand, unless it is required as an emergency procedure.
  • After the procedure is complete, the catheter will be removed.
  • If the catheter was inserted into your groin, the nurse or cardiologist may apply pressure to the entry site for about 10 minutes to stop any bleeding.
  • Alternatively, a number of different plugs or clips may be used to seal or close up the wound.
  • If the catheter was inserted through your arm, a tight dressing will be applied for around 2 to 3 hours.
Last updated: 15 May 2015

Continue to next section: Risks of cardiac catheterisation and coronary angiography