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Cardiac Computerized Axial Tomography

What is cardiac computerized axial tomography?

  • A cardiac computed tomography is a test that is used to take pictures of your heart. It is also called a cardiac CT. This test is done using x-rays and a computer. The CT scan machine is shaped like a large ring, and has a table that goes through it.
  • A cardiac CT may be done with or without contrast (dye). Dye is a type of liquid that is put into your blood vessels. The dye helps caregivers see problems with your heart and it's blood vessels. It will also show if your heart is working as it should. Certain heart conditions can cause chest pain or trouble breathing. A cardiac CT may show the cause of your symptoms. The results of your cardiac CT will help you and your caregiver decide on the best treatment for you. You may need other tests to help your caregiver plan your treatment.

Why might I need a cardiac computerized axial tomography?

  • Cardiac CT without contrast: This test may be done for calcium scoring. Calcium scoring is a way to measure how much calcium is in the blood vessels of your heart. Too much calcium may block your blood vessels. Blocked blood vessels in your heart increases your risk of having a heart attack. A cardiac CT done for calcium scoring can show your heart attack risk, and help caregivers plan your treatment.
  • Cardiac CT with contrast:
    • This test may be done because you have signs and symptoms of a heart problem. This test can show heart problems such as blocked or damaged blood vessels, or an infection. It can also show tumors (growths) or blood clots. You may have had tests to check for a heart condition, but the results of those tests are not clear. A cardiac CT may be needed to help explain the results. With the results of a cardiac CT and other tests, you and your caregiver can plan your treatment.
    • You may have a heart disease that needs to be treated with surgery. You may need to have a device such as a pacemaker placed in your heart. The vessels in your heart may need to be cleaned out and opened wider. Doing this will allow blood to flow through them more easily. A cardiac CT may be done before surgery so that caregivers can see the vessels and plan for your surgery.

How do I prepare for a cardiac computerized axial tomography?

  • Ask your caregiver if you need to stop taking your usual medicines before your test. Your caregiver may give you medicine to slow down your heartbeat. Having a slower heart beat will help the CT machine take pictures of your heart as it beats. If dye will be used during your test, tell your caregiver if you are allergic to shellfish (lobster, crab, or shrimp) or iodine, as you may also be allergic to the dye. You may be given medicine to decrease the risk of having an allergic reaction. If you have kidney problems or other health conditions, tell your caregiver. You may need to have blood taken and tested before your scan. You may also need to drink more liquids before the CT scan than you usually do. Ask your caregiver how much liquid to drink before and after your CT scan.
  • Do not eat or drink anything that has caffeine for at least six hours before your test. This includes coffee, tea, soda, chocolate, and some sports drinks and bars. Do not eat any food three hours before your test. Before the CT scan, drink liquids that have no caffeine, such as water. Ask your caregiver if you need to make other changes to what you eat or drink before your cardiac CT. If you have diabetes, ask your caregiver about what you may eat and drink before your CT scan. Ask him if you need to change how much or when you take your medicine. Ask him if you should check your blood sugar more often before or after having the CT scan.
  • Tell your caregiver if you are afraid of small spaces. Being inside the CT machine may make you worried or scared. Your caregiver may offer you medicine to help you relax. If you are female, tell your caregiver if you are or think you might be pregnant. A cardiac CT may cause devices, such as pacemakers and drug infusion pumps, to stop working correctly. Tell your caregiver if you use any medical devices. The device may need to be turned off before your cardiac CT.

What happens during a cardiac computerized axial tomography?

  • You will be asked to change into a hospital gown. Caregivers will ask you to take off any metal jewelry. You may have one or more IV tubes placed into a vein in your arm. Through the IV tube you will be given medicine and liquids. Your heart and blood pressure will be watched by caregivers during the CT scan. You will be taken to a room with the CT machine. The CT machine may be noisy.
  • You will lie down on a movable table. The table will be moved inside the CT machine. Caregivers may give you dye through your IV. As the dye is given, you may feel warm, and the area where your IV is may hurt. During your test, you may be asked to hold your breath for a few seconds. You will need to lay still during your test. The scan may take ten minutes or less.
    Computerized Axial Tomography Scan

What happens after a cardiac computerized axial tomography?

If you use a device such as a pacemaker or infusion pump, caregivers will check to see that it is working as it should. Caregivers will check your blood pressure and heartbeat after your cardiac CT. If dye was used, you may have blood tests to check your kidneys. Ask your caregiver when you may go home. Ask him when you will be told the results of your cardiac CT. Do not drive for three hours after having your cardiac CT.

What are the risks of cardiac computerized axial tomography?

  • There is a small chance that x-rays may put you at higher risk of getting cancer. A cardiac CT may not show certain heart problems. The results of the scan may show a problem that is not really there. If you use a medical device such as a pacemaker, it may not work right during or after your CT scan. Your kidneys may be damaged by dye, if it is used during your CT scan. You are at a higher risk of this happening if you have diabetes or kidney disease. You may have an allergic reaction to the dye.
  • If you do not have a cardiac CT, a heart problem may not be found. The heart problem may not be treated as it should be. Your signs and symptoms such as chest pain may get worse, and you may even die. Talk to your caregiver if you are worried or have questions about your CT scan.

Where can I find more information?

  • American Heart Association
    7272 Greenville Avenue
    Dallas , TX 75231-4596
    Phone: 1- 800 - 242-8721
    Web Address:

When should I call my caregiver?

Call your caregiver if:

  • You cannot make it to your cardiac CT.

When should I seek immediate help?

Call 911 or an ambulance if you have any signs of a heart attack:

  • Discomfort in the center of your chest that feels like squeezing, pressure, fullness, or pain, that lasts for more than a few minutes or keeps returning
  • Discomfort or pain in your back, neck, jaw, stomach, or one or both of your arms
  • Feeling sick to your stomach
  • Having trouble breathing
  • A sudden cold sweat, particularly in combination with chest discomfort or trouble breathing
  • Feeling very lightheaded or dizzy, particularly in combination with chest discomfort or trouble breathing

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

Learn more about Cardiac Computerized Axial Tomography

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.