Cardiac CTA or Coronary CTA

Cardiac computed tomography, or cardiac CT, is a painless, heart-imaging test that uses an x-ray machine to take clear, detailed, 3-D pictures of your heart. The test uses the aid of a computer with CT technology and intravenous (IV) contrast dye to visualize your arteries. It helps to determine whether fatty deposits or calcium deposits have built up in the coronary arteries (arteries that provide blood flow to the heart). During a cardiac CT scan, the x-ray machine will move around your body in a circle and take pictures of your heart. Each picture that the machine takes shows a small slice of the heart.

The test is non-invasive, only requiring an intravenous injection of contrast dye. If the patient has an iodine allergy, he/she should inform the staff several days before the exam time.

You may be a candidate for this test if your doctor wants to evaluate the following:

  • The heart structure
  • The coronary arteries and cardiac veins
  • The pulmonary arteries and pulmonary veins
  • The thoracic and abdominal aorta
  • The sac around the heart (pericardium)

How to Prepare

  • No sugar, caffeine, energy drinks or tobacco 12 hours prior to test.
  • No decongestants, Excedrin or antihistamines 12 hours prior to test.
  • No food or drink four-hours prior to test.
  • Do not use Viagra or any similar medication on the day prior to the exam.
  • Drink at least 24 oz of water the day prior to test.
  • Avoid metal on clothing such as snaps or jewelry.
  • Medications are reviewed individually.
  • Allow 30 minutes to an hour for testing.

If you take medicines for diabetes, ask your doctor whether you will need to change how you take them on the day of your cardiac CT scan.

Tell your doctor if you:

  • Are pregnant or may be pregnant. You should not have the scan if you’re pregnant. The x-rays may harm the developing fetus.
  • Have asthma or kidney problems or are allergic to any medicines, iodine, and/or contrast dye reaction. You will need to be premedicated if you have a history of intravenous dye or contrast allergy.

Taking pictures of the heart can be challenging because the heart is always beating (in motion). A slower heart rate between 50-60 beats per minute is ideal to help produce diagnostic quality pictures. Your doctor may give you medicines called beta-blockers or calcium channel blockesr to help slow your heart rate. Three to five doses of the medicine will be given by mouth (a few days prior to the exam) and if needed, injected into a vein (on the day of the exam).

What To Expect During a Cardiac CT

Contrast dye (iodine) will be used during the cardiac CT scan.

  • A small needle connected to an intravenous (IV) line will be put in a vein in your hand or arm. The contrast dye will be injected through the IV during the scan. You may have a warm feeling during the injection. The dye will highlight your blood vessels on the x-ray pictures from the cardiac CT scan.
  • The technologist who operates the cardiac CT scanner will clean areas of your chest and place small sticky patches on those areas. The patches are attached to an EKG (electrocardiogram) machine to record the electrical activity of your heart during the exam.
  • The technologist can see you through a glass window and talk to you through an intercom system.
  • Moving your body can cause the pictures to blur. You will be asked to lay still and hold your breath for short periods, while each picture is taken.
  • A cardiac CT scan usually takes about 15 minutes to complete. However, it can take over an hour to get ready for the test (this will depend on your heart rate) and for the medicine to slow your heart rate.

What to Expect After the Procedure

After the test, patients can return to their normal activities. Your physician’s office will call you with the results of the scan.

While the CT scan is a low-risk procedure, some individuals may have an adverse reaction to the contrast dye and could develop a rash following the injection. These symptoms usually resolve on their own. Antihistamines and or steroids can be administered for the relief of symptoms.