Pharmacological Nuclear Stress Test

What is an Pharmacologic Nuclear Stress Test?

Regadenoson, otherwise known as Lexiscan, is a medicine that causes blood vessels to expand, especially those in the heart. In this way it acts like exercise.  This medicine is used for patients who cannot use a treadmill but need a stress test. It is always used together with a radioisotope to make a blood flow image of the heart (see Nuclear Stress Test).

What can I expect the day of my test?

  1. No food for 4 hours prior to the test
  2. No caffeine (coffee, tea, soda, chocolate, etc.) for 24 hours prior to the test (caffeine causes the regadenoson not to work)
  3. An intravenous catheter (a small tube) will be placed in a vein on your arm
  4. The radioisotope will be injected at rest
  5. After approximately 45-60 minutes, a scan will be done of your heart (most often this will be done with you lying on your back with arms over your head under a detection camera, occasionally it is done sitting in a special chair),  the scan lasts 15 to 30 minutes.
  6. Following the scan adhesive patches will be placed on your skin to monitor your electrocardiogram
  7. While lying supine the Regadenoson will be injected through the intravenous catheter for 4 minutes
  8. 2 minutes after Regadenoson is begun the radioisotope will be injected
  9. You may be asked to bend your arm up and down during the regadenoson
  10. You may feel flushed or have shortness of breath, chest discomfort or a headache, these feelings stop 30 seconds after the regadenoson is stopped
  11. In 30-60 minutes, you will have the scan performed again post “exercise.” During this time, you will be asked to eat something and will be provided a small snack. Eating helps improve the images.
  12. Expect to be at the testing location for 3 hours