A nuclear stress test (NST) is a standard diagnostic procedure used to evaluate blood flow to the heart muscle, both at rest and during physical exertion or medication-induced stress. This test involves injecting a small amount of a radioactive tracer (radiotracer) into your bloodstream to create images of your heart. Because this substance temporarily makes you a source of low-level radiation, precautions are designed to minimize potential exposure to loved ones and pets until the radiotracer has naturally left your body.
Understanding the Radioactive Tracer
The radiotracer most commonly used in these tests is Technetium-99m (Tc-99m), which is designed specifically for medical imaging. Tc-99m has a relatively short half-life of approximately six hours, meaning its radioactivity decreases rapidly over the first day following the injection. The body naturally eliminates the radiotracer through physical decay and biological excretion. While decay reduces the radioactivity within your body, the remainder is flushed out primarily through urine and, to a lesser extent, feces. Most of the radiotracer is eliminated from your system within 24 hours of the test. Drinking plenty of fluids, such as water, after the procedure helps speed up this biological clearance process.
Direct Safety Guidance for Pets
Pets often spend prolonged periods in extremely close proximity to their owners. For the first 12 to 24 hours after your nuclear stress test, take simple, actionable steps to increase the distance between you and your animal companions. This temporary separation minimizes the chance of radiation exposure to your pet.
During this initial 24-hour window, avoid holding your pet on your lap or having them sit directly next to you for extended periods. Maintain a distance of at least three to six feet from your pet whenever possible, as this distance is sufficient to significantly reduce the radiation dose they receive. Do not allow your dog or cat to sleep in the bed with you for the first night following the test. If you must pet your animal, keep the interaction brief and wash your hands immediately afterward to avoid transferring any trace amounts of radioactive material. These measures are especially important for smaller pets due to their size and faster metabolism.
Essential Home Hygiene and Contact Rules
Adopt specific hygiene practices to protect all close contacts and keep your home environment safe during the first day. The main goal is to prevent the transfer of any excreted radiotracer, which is primarily found in bodily fluids.
Hygiene Practices
After using the toilet, flush twice and wash your hands thoroughly with soap and water. This ensures that any residual radiotracer in the urine is quickly and completely removed from the toilet bowl. You should also use separate bath towels and wash your linens and clothing separately from the rest of the household’s laundry for the first 24 hours.
Vulnerable Individuals
Extra caution is necessary when interacting with vulnerable household members, such as young children and pregnant individuals. Because a developing fetus or a young child’s rapidly dividing cells are more sensitive to radiation, maintain a greater distance from them for 24 to 48 hours. Avoid sharing eating utensils, drinking glasses, or food with anyone during this period to prevent the accidental transfer of fluids.