Dual Isotope Cardiac Stress Test

What is a Dual Isotope Cardiac Stress Test?

A dual isotope or nuclear stress test is a diagnostic nuclear imaging study that uses radioactive tracers, called Cardiolite and thallium, to produce images of the heart muscle. When combined with stress, either through exercise or use of a pharmacological agent, the dual isotope scan helps determine if the heart muscle is getting the blood supply it needs.

A dual isotope stress test consists of two parts, rest and stress:

  1. Thallium will be administered by injection through your IV while you are at rest, and a special camera will take pictures of your heart.
  2. Cardiolite will be administered to you one other time by an IV injection during the stress portion of the test, and additional pictures will betaken of your heart.

This allows the doctor to compare the amount of blood flowing through the heart muscle during stress and at rest.

The exercise or stress portion of the test is accomplished by walking on a treadmill. Some patients who are unable to walk on a treadmill may need to have a chemical stress test which simulates exercise through the dilation of the coronary arteries.

What are uses of a Stress Test?

A stress test can be used to test for heart disease. Stress tests are tests performed to determine the amount of stress that your heart can manage before developing either an abnormal rhythm or evidence of ischemia (not enough blood flow to the heart muscle).

This test helps to determine which parts of the heart are healthy and function normally and which are not.

How do I prepare for Stress Test?

Do not eat or drink for four hours prior to the test, and consume no caffeine for 24 hours prior to the test.

Avoid any strenuous physical activity on the day of the test because you will need to exert yourself maximally if you are doing an exercise test.

Bring busy material. You will have periods of waiting throughout the test so bring a book, newspaper, knitting or something. to keep you busy.

No smoking four hours prior to the test. Smoking may interfere with the test results. (You shouldn’t be smoking anyway!)

Wear a comfortable two-piece outfit and comfortable shoes. A hospital gown can be provided and men may be asked to take off their shirt.

Do not wear oils or lotions before your test. Small sticky patches (electrodes) will need to stick to your chest.

Your physician may also ask you to stop taking some of your heart medications on the day of your test. If you have any questions about your medications, ask your physician.

Note: Do not discontinue any medication without first talking to our office.