Thallium stress test is a kind of myocardial perfusion imaging test which involves the introduction of a small amount of a radioactive substance into the bloodstream in a state when the heart is beating rapidly. The objective of thallium stress test is to detect any blockages in the coronary arteries that might cause an insufficient supply of blood to certain portions of the heart. The test is just like an ordinary exercise stress test, except that it involves the injection of thallium into the body before the camera scans images of your heart. You do not need to take any special precautions before the test. You may be asked by your doctor to shortly discontinue the consumption of certain kinds of medicines, such as those meant for treating asthma and angina, as these may interfere with the test results. Also, you would be required to stop consuming caffeinated food and beverages a couple of days before the test and to stay away from food from the night before the test. Before the test, you would be asked to change into comfortable loose garments. Though the actual procedure is not very complicated and may be conducted by a medical assistant, it is advisable and reassuring if your doctor is around to supervise the whole process. You would be asked to walk on a treadmill for some time.
If you have severe asthma or find it painful to exercise because of chronic body pains then your doctor may advise the assistant to administer to you some form of medication that induces the heart to beat faster without requiring you to actually undergo physical toil. The rate at which your heart beats is monitored and once it reaches the optimum level, an injection containing a small amount of a radioactive substance is used to introduce the chemical into your bloodstream. After this, you will be asked to lie still on a table for a few minutes. Once the thallium begins to circulate in your heart muscles, a special camera is used to obtain images of your heart. Depending on the concentration of the radioactive substance in the heart muscles, your doctor will be able to determine if enough blood is being supplied to your heart under conditions of physical stress, and whether blood is being circulated uniformly in all parts of your heart. On the basis of a comparison between the activity of your heart under stress and during rest, your doctor will recommend appropriate treatment.
Submitted by M T on February 14, 2010 at 10:33