What is a nuclear stress test?
A nuclear stress test shows how well blood flows through your heart and arteries while you are resting and during physical exertion. In this test, a small amount of radioactive substance is injected into your body. This substance allows images of the heart to be recorded so that your doctor can see:

How well the heart is pumping blood
If a part of the heart has been damaged
If any of the arteries that feed the heart are blocked

What happens during the test?
Two sets of images will be taken � one while you are resting and one after you have exercised. This test is usually done in a special area called a lab. images will be taken while you are resting:

You will be asked to lie down on an examining table. An IV will be placed into a vein in your arm or hand. A radioactive substance will then be injected through the IV. You will need to lie still with your arms above your head for a few minutes to allow the substance to circulate through your body.

You may be taken to another area of the lab where a special camera reads traces of the radioactive substance and sends images to a monitor. By looking at the monitor your doctor can see how blood flows through your heart and arteries.

Your exercise test:
Before the exercise party of the test, small disks called electrodes will be placed on your chest. The electrodes are connected to an electrocardiogram machine. An electrocardiogram charts your heart�s electrical activity.

You will then walk on a treadmill or ride a stationary bike for a few minutes. Your rate of exercise will slowly increase.

You will be asked how you are feeling. Be sure to report any symptoms you may have, such as pain or discomfort in your chest, arm or jaw, shortness of breath or dizziness.

If you are unable to exercise, you will be given medications that cause the heart and blood vessels to react as they would during exercise. The medications may cause sensations such as tightness in the throat and chest along with a hot, flushed feeling. This is normal and will go away in 4-5 minutes.

images will be taken after you have exercised:
After several minutes, you will be given another injection of the radioactive substance.

You will be asked again to lie down for another scan of your heart. images taken at this time show how blood moves through the arteries to all areas of the heart during physical exertion. Your doctor will compare the images that were taken before and after exercise.

The test results will be discussed with you after your doctor has had a chance to review all of the information.

Your doctor's recommendation:
Feeling uncertain about your health can be stressful for you and your family. Because you have had this test, you know that any advice about treatment is based on facts discovered during your test. You may be advised to have more tests or you may need medication or a surgical or nonsurgical treatment. Whatever your doctor�s recommendation, you can rest assured that it is based on the best possible information.

Do not eat or drink anything for 4-6 hours before your test.

Do not eat or drink any caffeinated products (like cola, Mountain Dew, tea, coffee or chocolate) for 12 hours before the test.

Report all of the medications you take. Ask if you should stop taking any of your medications before the test. Some medications, such as blood pressure medication, nitroglycerin and beta blockers can interfere with the test.

Do not take over-the-counter medications that contain caffeine before your test. Some medications (diet, pills, Anacin, Excedrin, Vanquish) contain caffeine.

If are pregnant or nursing, tell the staff before your test.

For people with diabetes:
If you take insulin, ask your doctor what amount you should take the day of your test. If you take diabetes pills, do not take your medication until after your test.

A nuclear stress test usually takes about 2 to 3 hours.

Ask your doctor when you can eat and drink.

Ask your doctor when you can take your medications.

Ask your doctor when you can return to your normal activities.

It is important to note that the radioactive substance used in this test is safe and will not harm your body. The substance will leave your body within a few hours.

Your test results:
The heart normally pumps more blood during times of physical exertion. If the test shows that blood flow is normal while you are resting, but not normal while you are exercising, your heart may not be getting enough blood during physical exertion.

If blood flow is not normal during rest and exercise, this may mean that a section of the heart muscle has been permanently damaged or that one or more of the arteries that supply part of your heart with blood may be blocked.

Test results will be discussed with you after your doctor has had a chance to review all of the information.