CT coronary angiography

Understanding the CT angiography procedure

Before you have your CT coronary angiography, you may be advised to temporarily take beta-blockers. These drugs will slightly slow your heart rate to improve imaging accuracy. You may also be given medication to help widen your arteries and make them easier to see. 

At the beginning of the procedure, an intravenous (IV) line will be inserted into your hand or arm to allow the contrast dye to be injected into your body. This dye is made from iodine, which prevents X-rays from being able to pass through it. As a result, your arteries will show up clearly during the imaging process. 

Once the contrast dye has circulated around your body, it will eventually be eliminated through your urines.

Electrodes will be placed on your chest to monitor your heart rate throughout the procedure. You’ll then be led onto a long table that moves slowly into the CT machine, ready for the imaging to begin. You’ll need to make sure you lie as still as possible while the machine is scanning, and you might be advised to hold your breath at certain intervals. 

The scanning should only take a couple of minutes and is completely painless. You may feel a hot flush when the dye is injected. You will likely hear the machine clicking and buzzing as it scans you. 

After the scan is complete, you should be able to go home straight away and continue with your normal day-to-day activities. 

Preparing for a CT coronary angiogram

If you book a CT coronary angiography with London Medical, we will provide you with all the information you need to know to prepare for your appointment.

Some of the things we might ask you to do include: 

• Avoid eating anything for four hours before your appointment
• Do not drink anything caffeinated in the 12 hours leading up to your appointment
• Stop certain medications that might interfere with the procedure 

If you are, or think you might be, pregnant, make sure to let us know beforehand, as a CT coronary angiography might not be suitable for you. 

You will need to change into a patient gown when you arrive. 

Although you shouldn’t eat anything four hours before, you can drink clear liquids — just make sure they aren’t caffeinated. 

Do not stop taking your usual medications unless advised otherwise by your doctor. 

Benefits and risks

Like all medical procedures, a CT coronary angiography does carry some risks. However, the benefits of receiving such accurate imaging of your arteries greatly outweigh the risks involved.

The main benefits of having a CT coronary angiography include: 

• It’s a non-invasive procedure
• The only pain you will experience is a slight pinch when the IV line is inserted 
• You can go home afterwards
• The images are extremely accurate and detailed
• No radiation will remain in your body after the scan
• Heart conditions can be accurately diagnosed and treated effectively

Although rare, complications can arise when having a CT coronary angiography. These risks can include: 

• An allergic reaction to the contrast dye – this is rare and your doctor will know about any allergies you may have beforehand
• Tissue irritation or damage at the site of the IV line – if some of the dye leaks out, it can irritate your skin and surrounding blood vessels

If you have severe kidney disease, you may not be suitable for this test as the contrast dye can cause complications. 

If you are breastfeeding, you must wait 24 hours before nursing to ensure no dye comes out in your milk.  

Understanding the results of the CT coronary angiogram

Your CT coronary angiography results will determine whether the blood supply to your heart is normal. If not, this could suggest a blockage or narrowing of your arteries, which will be visible in the images. 

Any further treatment you need as a result of the angiogram will be discussed with you, and you’ll be able to ask any questions that you might have about your results.