“Why do a nuclear medicine stress test?”

To begin with, following your doctor's advice is usually a much better idea than not following it, especially if your doctor is aware of the specific nature of your medical risks and has helped you before. Some positive aspects of nuclear tests include less radiation exposure than most competing CT based x ray tests and a long history of what the results of the nuclear tests mean and how to interpret them. Stress echocardiography is attractive in the literature with no ionizing radiation risk; however, expertise in performing it well is scarce and in everyday practice it is much less attractive than in the literature and tends to have a value closer to what most insurance companies reimburse for it, which is very little. MRI tests of cardiac function are also very attractive in the literature and in centers where they are performed well, such as the University of Alabama Birmingham, are very effective tests. Outside of centers that have dedicated expertise in cardiac MRI, results are much less reliable and cardiac MRI is usually very expensive and more difficult to get insurance covered. Any stress test has some risk, but in the hands of qualified technologists and physicians, these risks are very low. You have also to consider the risk of not doing the stress test. Coronary artery disease remains the number one cause of death in your age group and it is usually preventable or treatable if diagnosed early and much more of a problem, even including fatality, when not properly diagnosed and treated. You could do a plain exercise ECG test, but the accuracy of these tests in women is only about 50% while the nuclear stress test has much higher sensitivity and specificity, near 85%. Nuclear cardiac PET scans have even higher sensitivity and specificity, approaching 95%, and lower radiation exposure when N-13 PET stress tests are available. Many insurances require a routine stress test before a Nuclear PET scan is approved, but if yours does not then the PET cardiac stress test is usually preferable.

When deposits form in the coronary vessels, it may decrease the flow to the heart. Cardiac catheterization can tell the amount of narrowing but not the functional significance. For the nuclear stress test a patient is stressed by exercise or drugs. If there is a functional narrowing of a vessel, there will be decreased blood flow to the area supplied by that vessel. We see that as decreased counts or brightness on the pictures. If that abnormality goes away when the heart is at rest, that means there is ischemia to that region and that vessel will likely need to be fixed.