A nuclear stress test measures blood flow to your heart muscle both at rest and during stress on the heart. It's performed similar to a routine exercise stress test, but provides images that can show areas of low blood flow through the heart and areas of damaged heart muscle.
A nuclear stress test usually involves taking two sets of images of your heart — one set during an exercise stress test while you're exercising on a treadmill or stationary bike, or with medication that stresses your heart, and another while you're at rest. A nuclear stress test is used to gather information about how well your heart works during physical activity and at rest.
You may be given a nuclear stress test if your doctor suspects you have coronary artery disease or another heart problem, or if an exercise stress test alone wasn't enough to pinpoint the cause of symptoms like chest pain or shortness of breath. A nuclear stress test may also be recommended in order to guide your treatment if you've already been diagnosed with a heart condition.