This test evaluates blood flow through the heart at rest and after exercise. It involves injecting Sestamibi, a substance that is slightly radioactive.
Before the test
In the 24 hours before the test, you should not have any food or drink containing caffeine (including tea, coffee, chocolate, cola or cocoa). Some medications may also be stopped 24 hours before the test. Consult your doctor about this.
On the morning of the test, you should not have breakfast, or anything to eat or drink (except water). Bring loose clothes and comfortable walking shoes or jogging shoes for walking on the treadmill.
During the test
The total time of the test is 4–5 hours.
ECG dots are attached to your chest and a small needle is inserted into a vein in your arm. This remains in place until the end of the test.
You then walk on a treadmill while your heart action and ECG are carefully monitored. (If you are unable to walk on the treadmill, a Persantin Sestamibi Heart scan may be ordered. The drug Persantin replaces the effect of exercise for this test, and acts by enlarging the arteries which supply blood to your heart.)
When your heart rate reaches the limit for your age, a small dose of Sestamibi will be given through the inserted needle and you will be asked to continue walking for one more minute. You should not notice any reaction from the injection.
Images (scans) of your heart will then be taken using a special camera. These show the distribution of blood supply to the heart muscle. It is important that you lie still during the scans.
After the initial images you should continue fasting, and must not exercise in any way for three hours. The images will then be repeated.
Sometimes extra pictures of the heart may need to be taken 18 hours later, the morning after the test.
Further analysis of this test is done by a computer, so no result is available at the time you go home. The result will be sent to your doctor.
This information was first published in You and Your Heart - an education booklet for patients, families and friends. © 2006 Northern Sydney Central Coast Area Health Service
