According to the American Heart Association, injections of thallium or sestamibi (radioactive substances) are used for nuclear stress tests. These tests are typically performed in conjunction with exercise tests using a treadmill or stationery bicycle, and provide nuclear imaging along with an EKG.
Function
The purpose of a nuclear stress test is to diagnose or evaluation problems, such as chest pains, the extent of an arterial blockage, the prognosis after a heart attack, safe levels for exercising and the evaluation of previous cardiac procedures.
Procedure
After reaching a maximum exercise level on the treadmill or bicycle, the radioactive substance is injected into the bloodstream. A special camera takes pictures to show the flow of blood to the heart. After two to three hours of rest, a second set of images is taken.
Results
Normal results will indicate appropriate blood flow during exercise and at rest. The American Heart Association indicates that abnormal blood flow during exercise, rest or both is indicative of blockage in one or more coronary arteries.
Risks
The potential risks include chest pain and fainting. Irregular heart rhythm and heart attack are rare. An EKG monitors the heart throughout the test to minimize these risks.
Considerations
If you are too ill to take the exercise test, or if you have physical limitations, a drug such as dipyridamole or adenosine can be administered to increase blood flow to simulate exercise.
Tags: blood flow, American Heart, American Heart Association, blood flow during, during exercise
