What To Expect Before Cardiac CT

Your doctor will tell you how to prepare for the cardiac CT scan. People usually are asked to avoid drinks that contain caffeine before the test. Normally, you're allowed to drink water, but you're asked not to eat for 4 hours before the scan.

If you take medicine for diabetes, talk with your doctor about whether you'll need to change how you take it on the day of your cardiac CT scan.

Tell your doctor whether you:

• Are pregnant or may be pregnant. Even though cardiac CT uses a low radiation dose, you shouldn't have the scan if you're pregnant. The x rays may harm the fetus.
• Have asthma or kidney problems or are allergic to any medicines, iodine, and/or shellfish. These problems may increase your chance of having an allergic reaction to the contrast dye that's sometimes used during cardiac CT.

A technician will ask you to remove your clothes above the waist and wear a hospital gown. You also will be asked to remove any jewelry from around your neck or chest.

Taking pictures of the heart can be hard because the heart is always beating (in motion). A slower heart rate will help produce better quality pictures.

If you don't have asthma, COPD (chronic obstructive pulmonary disease), or heart failure, your doctor may give you a medicine called a beta blocker to help slow your heart rate. The medicine will be given by mouth or injected into a vein.