University of Iowa Departments of Radiology and Internal Medicine
Peer Review Status: Internally Peer Reviewed
First Published: Unknown
Last Revised: March 2003

What is a Myocardial Perfusion Scan?

This scan is a two-part imaging procedure which uses two radioactive tracer doses, a drug (adenosine or dobutamine), and a camera connected to a computer to produce pictures of blood flow to the heart muscle.

The scan will tell us if there are areas of heart muscle that do not receive enough blood either at rest or during stress. The drug is used to increase blood flow to the heart and is used in place of exercise.

The total time required for this test is approximately three hours if the patient weighs less than 225 pounds. If the patient weighs more than 225 pounds, the test will be completed on 2 separate days..

Preparing for a Myocardial Perfusion Scan

1. Do not eat or drink anything except water in the 12 hours before the exam.
2. It is extremely important not to take any theophylline-based drugs or oral dipyridamole (Persantine) for 48 hours before the scan. Do not eat or drink any products containing caffeine in the 12 hours before the scan. If these instructions are not followed, the test cannot be completed. Be sure to ask your doctor if any medications should be withheld before the procedure.
3. Take any other scheduled medications except as noted above.
4. Bring a book, magazine, or something else to do while you wait for your scan.
5. Diabetic patients should talk with their doctor about any insulin changes that might be needed due to food restriction the day of the scan.

In the Nuclear Medicine Divison

1. You will be asked your medical history including medications you are now on. Please bring a list of your medications.
2. You will be told about the scan, then asked to sign a consent form.
3. You will be asked to change into a hospital gown. Female patients will be asked to remove their bras before any imaging session.
4. An IV will be inserted in a vein in your arm.

The Resting Scan

1. The first radioactive tracer dose will be injected into the IV.
2. Pictures of your heart will be taken by a camera and recorded by a computer approximately 30-40 minutes after the injection.
3. Pictures usually take 20 minutes to complete.

The Drug Stress Scan

1. The drug stress part of the scan will begin as soon as possible after the resting scan is completed. The waiting time will depend on the number of patients scheduled.
2. The stress test on your heart will take 6-12 minutes depending on the medication used..
3. The second radioactive tracer dose will be injected during the stress test.
4. Pictures of your heart are taken 30 minutes after the radioactive agent is injected.
5. Pictures usually take 20 minutes to complete.
6. A doctor or physician assistant will monitor your test.

Considerations

Please notify the Nuclear Medicine staff and your doctor if you are pregnant or think you might be pregnant. In general, radioactive agents should not be administered to pregnant women. In certain cases, however, the procedure can be performed safely during pregnancy.

It is very important that you hold very still during each scanning procedure. If you feel this may be a problem, please tell your doctor.

The radioactive exposure that you receive from the procedure is approximately equivalent to the average background radiation exposure received by each member of the general public in 8 years. Also, this amount of radiation is less than one-half the annual radiation exposure allowed for x-ray technologists and nuclear medicine technologists.