You are given a mild sedative prior to the test. An intravenous line is started in your arm to allow for the administration of medication during the procedure. A cardiologist then inserts a catheter through a small incision in an artery in your arm or groin after cleansing and numbing the site.

The catheter is then carefully threaded into your heart using x-ray images called fluoroscopy to guide the insertion. When the catheter is in place, dye is injected to view the left heart, the blood vessels that supply the heart (the coronary arteries), or both.

Food and fluid are restricted for 6 to 8 hours before the test. The procedure takes place in the hospital. Sometimes, admission the night before the test is required. Otherwise, admission as an outpatient or inpatient on the morning of the procedure is required.

A health care provider will explain the procedure and its risks. You must sign a consent form for the procedure. You will be given a mild sedative 1/2 hour before the procedure. The procedure may last from 1 to several hours. You will wear hospital clothing.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:

• Infant test or procedure preparation (birth to 1 year)
• Toddler test or procedure preparation (1 to 3 years)
• Preschooler test or procedure preparation (3 to 6 years)
• Schoolage test or procedure preparation (6 to 12 years)
• Adolescent test or procedure preparation (12 to 18 years)

The procedure takes place in a radiology department or cardiac diagnostic laboratory. You will be given sedation to relax you prior to the procedure, but you will be awake and able to follow instructions during the test. You will remain on a stretcher throughout the entire test.

You are given local anesthesia to insert the catheter, and the only sensation is one of pressure at the site. A puncture is made into an artery in your arm, neck, or groin for threading the catheter into your heart. Occasionally, a flushing sensation occurs after the dye is injected. Discomfort may arise from having to lie still for prolonged periods of time.