A nuclear stress test without a treadmill is called a pharmacological or chemical stress test. This is used for individuals who are unable to exercise adequately on a treadmill due to physical limitations or other health concerns.
Nuclear stress test procedure phases
1. Nuclear stress test preparation
Before the test, you should avoid caffeine-containing products for a certain period, as caffeine can interfere with the accuracy of the test. If are taking medications you should temporarily stop before the test.
2. Resting Phase
A small amount of a radioactive tracer, usually technetium or thallium, is injected into a vein in your arm. Wait for some period to allow the tracer to be absorbed by the heart muscle during rest.
3. Imaging
You will be positioned under a gamma camera, which detects the radioactive tracer. This camera takes images of your heart from different angles during the resting phase. This provides a baseline assessment of blood flow to the heart at rest.
4. Stress Induction (Pharmacological Stress)
Instead of exercising on a treadmill, a pharmacological stress agent such as adenosine, dipyridamole, or dobutamine is administered through an intravenous (IV) line. It will simulate the effects of exercise on the heart by increasing blood flow. The stress agent may be administered gradually to achieve the desired stress level.
5. Second Set of Images
After the stress is induced, another set of images is taken using the gamma camera. These images capture the blood flow to the heart during stress, allowing a comparison with the resting images.
6. Comparison and Analysis
The resting and stress images are then compared to assess any differences in blood flow. Areas of the heart that receive less blood flow during stress may indicate potential issues, such as blocked arteries or reduced cardiac function.
7. Post-Test
Once the imaging is complete, the radioactive tracer naturally decays over time, and it is eliminated from the body through urine.