A CT coronary angiogram (CTCA) is a non-invasive imaging test that uses advanced X-ray equipment to visualise the coronary arteries — the vessels that supply blood to the heart muscle. It is used to assess whether the coronary arteries are narrowed or blocked.
Why is it Done?
A CTCA is used to:
- investigate chest pain or shortness of breath where coronary artery disease is suspected
- rule out significant coronary artery disease before catheter ablation or other cardiac procedures
- assess the anatomy of the pulmonary veins prior to atrial fibrillation ablation
What to Expect
A contrast dye is injected into a vein in your arm to highlight the coronary arteries on the X-ray images. You will lie flat while the scanner takes a rapid series of images, usually over just a few seconds. If your heart rate is high, you may be given a medication beforehand to slow it briefly — this produces clearer images.
The full appointment, including preparation and recovery, takes around 60 minutes. After the scan it is advisable to drink plenty of water to help your kidneys clear the contrast dye.
Risks
The contrast dye is safe for most people but carries two small risks:
- Allergic reaction — ranging from a mild rash to, very rarely, a more serious reaction. You will be asked about any history of contrast allergy before the test.
- Kidney impairment — in patients with pre-existing kidney disease the contrast dye can temporarily worsen kidney function. Your kidney function will be checked beforehand if there is any concern.
The scan also involves a small dose of radiation, similar to a few months of background environmental exposure.