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Cardiac CT Angiogram

Patient information A-Z

This leaflet is intended for patients attending for a Cardiac CT Angiogram.

Preparation before your scan

  • Avoid caffeine completely for a minimum of 8 hours before your scan. Examples include; coffee, tea, energy drinks, fizzy drinks, chocolate and certain cold and flu medications. If in doubt please check the label.
  • Apart from the above you may eat and drink as normal before your scan.
  • Please continue to take your routine medications, including beta blockers (such as Bisoprolol) even on the day of your scan.
  • If you are taking tablets for erectile dysfunction- for example sildenafil (Viagra), tadalafil (Cialis) or vardenafil (Levitra)- you should stop taking these for three days before your scan appointment. Let the radiographer know if you routinely take these medications.
  • Please don’t apply any body lotions on the day of your scan e.g. body creams
  • Please fill in the attached questionnaires and bring them with you to your appointment.

Please tell us before your appointment if you have:

  • an allergy to iodine-based contrast dye
  • any kidney problems affecting kidney function
  • you require an interpreter – interpreters need to be booked in advance.

About the scan

  • The CT (computed tomography) scanner produces images of inside the body using x-rays to generate cross sectional ‘slices’ of the body.
  • A cardiac CT angiogram will localise this process to the heart in order to view the small blood vessels supplying blood to the heart and the anatomy of the heart itself.
  • These images are enhanced by using an iodine based contrast dye that highlights the blood vessels on the scan.
  • The scan is performed in two parts. The first part is a unenhanced scan (no contrast injection) which looks for calcification in the blood vessels around the heart.
  • Depending on what is identified on this scan, we will progress to the second part where you have an injection of dye to get a better picture of the blood flow in these vessels. As the contrast dye shows up white the same as any calcification, we do the first scan without the injection.
  • Once the scan has been completed the Radiologist (doctor who reports the scan) analyses the scan using specialised software to make their report.
  • You will not receive any results on the day and results will be sent back to your referring team who will organise a follow up appointment with you.

Scan procedure

  • You will be asked to undress from the waist up and to wear a hospital gown (if you would like you can bring your own dressing gown to wear).
  • Please don’t wear anything metallic around the chest area e.g. necklaces
  • If worn, a sports bra without any metal is preferable.
  • A cannula (needle) will be inserted into your arm which will be used for the contrast dye injection.
  • You will have your heart rate monitored via an (ECG) monitor. To do this you will have four small stickers placed on your chest. Hairy areas may need shaving. Whilst ECG tabs are being placed their will be another staff member acting as a chaperone as per the Hospital policy.
  • Blood pressure will be checked before and after the scan.
  • There may be two addition medications administered:
  • A beta blocker injection: this temporarily slows your heart rate down for 20-30 minutes allowing clearer images of the heart.
  • Glyceryl trinitrate (GTN) spray: this temporarily dilates the blood vessels for the scan. GTN can cause a short lasting headache but should wear off after 15-20 minutes. If you have been prescribed GTN spray please bring it with you.
  • You will be asked to place your arms above your head for the duration of the scan (approximately five minutes).
  • At this point the scan will start, you will be asked to hold your breath and be given the injection of contrast dye, after which it is common to feel a short-lived hot flush all over the body.
  • Once adequate images have been taken you will be asked to wait 15 minutes before your cannula is removed.
  • Including preparation the procedure should last approximately 30 minutes.

After the scan

  • You may eat, drink and carry out activities as normal.
  • You may drive home; we recommend allowing 30 minutes after your scan for medications to wear off. Do not drive if you still feel dizzy or light headed.
  • Your scans will be looked at by our radiologist and the results forwarded to the referring clinic; please allow two weeks.
  • If you have a future appointment to be seen in clinic then the results will be made available for that appointment.

It is unlikely however, should you feel unwell in any way or have any sign of an adverse reaction after your scans please contact your GP immediately.

If you have any questions about medications please contact your doctor in clinic who referred you for the scan. They are the best qualified person to deal with such questions.

Privacy and dignity

Same sex bays and bathrooms are offered in all wards except critical care and theatre recovery areas where the use of high-tech equipment and/or specialist one to one care is required.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151