Nuclear Stress Testing (exercise and pharmacological)
With this type of testing, a scan of the blood flow through the heart muscle is done usually at rest and with some sort of stress (exercise or chemical–in this case, adenosine). Much like the other stress tests described, if the individual is capable of walking, the test will be done with exercise; if not, by medication. A safe, radioactive substance like Technetium or Thallium is injected followed by camera images as the blood flows during rest and during stress. By comparing the images at rest to during stress, the blood flow can be determined to be normal, or obstructed by blockages. This type of testing is usually done before the more invasive angiogram and can be done in the office. Pharmacologic stress testing, established after exercise testing, is a diagnostic procedure in which cardiovascular stress induced by pharmacologic agents is demonstrated in patients with decreased functional capacity or in patients who cannot exercise. Pharmacologic stress testing is used in combination with imaging modalities such as radionuclide imaging and echocardiography