What is a Nuclear Thallium Stress Test?

A nuclear stress test is similar to a cardiac stress test. These tests measure the heart's blood pressure and electrical activity before and after exercise (stress). In addition to electrocardiogram (EKG/ECG) readings, a nuclear stress test also provides images.

This is done by injecting a safe amount of radioactive material into the bloodstream. The material mixes with the blood, and is carried to the heart. A scanner detects the radioactive material in the heart and makes images of the heart muscle.

Guidelines for having a nuclear stress test include:

  • Do not eat or drink for 4 hours before the test
  • Do not eat or drink caffeine for 24 hours before the test
  • Do not smoke on the day of the test
  • Do wear comfortable clothes for the test

A nuclear stress tests usually takes 2 to 3 hours.