What is a Cardiac CT?
Cardiac CT is a heart-imaging test that uses CT technology to take many detailed pictures of your heart and its blood vessels. CT stands for computed tomography, which is a type of X-ray that produces three-dimensional (3D) images of the body.
Why is a Cardiac CT done?
A cardiac CT scan is done to:
- Identify narrowing (stenosis) in the coronary arteries and blood vessels that supply blood to the heart or other parts of the body
- Diagnose various heart conditions, such as congenital heart defects, valve problems, pericardial diseases, blood clots, tumours, or signs of a heart attack
- Plan or evaluate treatments, such as bypass surgery, stent placement, or valve replacement
- Assess the risk of a heart attack by checking for calcium or plaque buildup in the arteries, which can indicate coronary artery disease or atherosclerosis
How should you prepare for Cardiac CT?
To prepare for Cardiac CT, you should follow the instructions given by your doctor, which may include:
- Not eating or drinking anything for a few hours before the test
- Avoiding caffeine and nicotine for 12 hours before the test
- Informing your doctor about your medical history, allergies, medications, or supplements
- Wearing comfortable and loose-fitting clothing
How is Cardiac CT done?
You will lie on a table that slides into a doughnut-shaped machine called a CT scanner. Electrodes will be attached to your chest to monitor your heart rate and rhythm. You may receive a medication called a beta blocker to slow your heart rate, and a spray or a pill called nitroglycerin to widen your coronary arteries. You may also receive an injection of a contrast dye into your vein to make your blood vessels more visible on the images. The CT scanner will rotate around your chest and take multiple X-ray images of your heart from different angles. The whole procedure usually takes about 15 to 30 minutes.
What are the benefits and risks of Cardiac CT?
Cardiac CT has many benefits including:
- It is noninvasive and painless
- It provides high-quality and detailed images of the heart and its blood vessels
- It can detect or rule out various heart problems, such as blocked or narrowed arteries, aneurysms, or tumours
- It can help plan or evaluate treatments, such as bypass surgery, stent placement, or valve replacement
- It can help prevent complications, such as heart attack or stroke
What are the risks of Cardiac CT?
Cardiac CT also has some risks, such as:
- It exposes you to radiation, which may increase your risk of cancer in the long term.
- It may cause an allergic reaction to the contrast dye, which can be mild or severe.
- It may not be suitable for some people, such as pregnant women, people with kidney problems, or people with metal implants or devices in their body.
- It may not provide clear or accurate images for some people, such as people with irregular heartbeats, obesity, or excessive chest movement.