What does the thallium stress test show?
If the test is normal during both exercise and rest, then blood flow through the coronary arteries is normal. (The coronary arteries supply blood to the heart muscle). If the test shows that perfusion (blood flow) is normal during rest but not during exercise (a perfusion defect), then the heart is not getting enough blood when it must work harder than normal. This may be due to a blockage in one or more coronary arteries. If the test is abnormal during both exercise and rest, there is limited blood flow to that part of the heart at all times. If no thallium is seen in some part of the heart muscle, the cells in this part of the heart are dead from a prior heart attack. They have become scar tissue.
