Nuclear Stress Test

What Is a Nuclear Stress Test?

A nuclear stress test is an advanced imaging study that shows how well blood flows to your heart muscle both at rest and under stress. A small, safe amount of a radioactive tracer is injected into your bloodstream, and a special camera takes detailed pictures of your heart. This gives your doctor a clear map of any areas that may not be getting enough blood flow.

Why Is It Done?

Your doctor may recommend a nuclear stress test if you have chest pain, shortness of breath, or other symptoms that suggest reduced blood flow to the heart. It’s especially useful when a standard exercise stress test isn’t enough to make a diagnosis. It can help determine how severe a blockage is, guide decisions about further treatment, and assess how well your heart is functioning after a heart attack or procedure.

What to Expect

The test is done in two parts (a rest phase and a stress phase) and typically takes 3 to 4 hours total. For each phase, you’ll receive a small injection of the tracer through an IV, followed by imaging. The stress phase may involve walking on a treadmill or, if you can’t exercise, receiving a medication that simulates the effect of exercise on your heart. The tracer injection may cause a brief warm feeling but is not painful.

How to Prepare

You’ll typically need to avoid caffeine for 24 hours and fast for 4 to 6 hours before the test. Ask your doctor whether you should skip any heart or blood pressure medications the morning of the test. Wear comfortable walking shoes and loose clothing. Plan to be at the office for most of the morning, as the test takes several hours to complete.