A computerized tomography (CT) coronary angiogram is an imaging test that looks at the arteries that supply blood to your heart. It might be used to diagnose the cause of chest pain or other symptoms.
A CT coronary angiogram relies on a powerful X-ray machine to produce images of your heart and its blood vessels. These tests are noninvasive and don't require recovery time. Coronary CT angiograms are increasingly an option for people with a variety of heart conditions.
A traditional (not CT-based) coronary angiogram requires that a flexible tube (catheter) be threaded through your groin or arm to your heart or coronary arteries. If you have known coronary artery disease, your doctor might recommend a traditional coronary angiogram because you can also receive treatment during that procedure.
Why is it done?
A coronary CT angiogram can check your heart for various conditions, but it's primarily used to check for narrowed or blocked arteries in your heart (coronary artery disease). If your test suggests that you have heart disease, you and your health care provider can discuss treatment options.
Risks
You'll be exposed to some radiation during the test. The amount varies depending on the type of machine used. We refer to a service with a very fast CT scanner that results in minimal radiation exposure. The risk of developing cancer from a CT angiogram isn't known, but it's small. However, you shouldn't have a CT angiogram if you're pregnant because of possible harm to your unborn child.
It's possible that you could have an allergic reaction to the dye used in the procedure. Talk to your doctor if you're concerned about having an allergic reaction.
How to Prepare
Your doctor should give you instructions about how to prepare for your CT angiogram. You can drive yourself to the appointment, and you'll be able to drive after your test.
Food and Medication
Usually, you'll be asked not to eat anything for about four hours before your test. You can drink water, but avoid caffeinated drinks 12 hours before your test, because they can increase your heart rate, which can make it difficult for your doctor to get clear pictures of your heart. If you're allergic to the dye used in the procedure, your doctor might ask you to take steroid medication 12 hours before the procedure to reduce your risk of a reaction.
Clothing and Personal Items
You'll need to remove clothing above your waist, as well as jewelry and glasses, and change into a hospital gown.
What you can Expect
CT angiograms are usually performed in the radiology department of a hospital.
Before the Procedure
Your doctor might give you a medication called a beta blocker to slow your heart rate, enabling the scan to produce a clearer image. Let your cardiologist know if you've had side effects from beta blockers in the past. Because of the fast scanner we use, you may not require any medication at all.
You might also be given nitroglycerin to widen (dilate) your coronary arteries. If you're allergic to contrast material, you might be given medication to lower your risk of a reaction.
During the Procedure
A technician will insert an intravenous (IV) line in your hand or arm to inject the dye that will make your heart's arteries visible on the images. Although the actual scanning portion of the test takes as few as five seconds, it may take up to an hour for the whole process.
The technician will place electrodes on your chest to record your heart rate. You'll lie on a long table that slides through a short, tunnel-like machine. During the scan you'll need to stay still and hold your breath so as not to blur the images. If you're uncomfortable in closed spaces, ask your doctor if you need medication to help you relax.
A technician will operate the machine from a room that's separated from your exam room by a glass window. There will be an intercom system that allows you and the technician to communicate with each other.
After the Procedure
After your CT angiogram is completed, you can return to your normal daily activities. You should be able to drive yourself home or to work. Drink plenty of water to help flush the dye from your system.
The images from your CT angiogram should be ready soon after your test. Usually, the cardiologist who asked you to have a CT angiogram should discuss the results of the test with you.
Results
Based on the results of your test, your health care provider will discuss with you whether you have a heart condition that needs treatment, whether you're at risk of developing heart disease and steps you can take to keep your heart healthy.