Nuclear Stress Test

Treadmill and Chemical Lexiscan

A Nuclear Stress Test is similar to an Exercise Stress Test, in that it measures the flow of blood to your heart both while it’s at rest and when it’s  working harder as a result of exertion as you walk on a treadmill. The difference is that for a Nuclear test, a radioactive dye is injected into your bloodstream. The dye helps show the flow of blood more clearly, revealing areas of lower blood flow, damaged or clogged arteries tied to coronary artery disease, and the size and shape of your heart. It can also help guide treatment.

If you are unable to undergo an adequate exercise stress, another test may be administered where a medicine called Lexiscan may be injected. Lexiscan dilates the arteries of the heart and increases blood flow in a similar way to exercise to help identify coronary artery disease.

How Should I Prepare the Day Before the Procedure?

Ask your doctor if you should avoid caffeine or certain medications the day before the test, because they can interfere with certain stress tests. You may also be asked not to eat, drink or smoke for two to four hours before the test, though you can still drink water. Plan to wear comfortable, loose-fitting work-out clothes such as shorts or sweatpants and jogging or tennis shoes.

What Happens on the Day of the Procedure?

The test may take from 2 - 4 hours. The technician will place sticky patches (electrodes) on your chest and arms or shoulders that are connected with wires to an electrocardiogram machine. The electrocardiogram records the electrical signals that trigger your heartbeats. A cuff on your arm also checks your blood pressure during the test. The technician will also insert an intravenous line (IV) into your arm or hand, and the dye will be injected through the IV. First, images will be taken of your heart at rest, then again after you’ve exercised. The two sets of images will be compared to show if there are areas of inadequate blood flow to part of your heart.

The radioactive material will naturally leave your body in your urine or stool, but drinking plenty of water will help flush the dye out of your system.

When Will I Get My Results?

Your doctor may be able to look at the results recorded during your test to see if your heart is functioning normally, and tell you the results the same day it's performed or at a follow-up appointment. The data from this test may also indicate the need for additional tests which your doctor will recommend.