Nuclear Stress Test
A nuclear stress test is usually performed when there is a strong suspicion of coronary artery disease (blocked or clogged arteries), heart damage (heart attack, infection, injury, drug abuse) or insufficient ventricle function (weakened or failing heart, low velocity blood flow). This type of stress test is often performed to check the current status of cardiac patients that have been diagnosed with heart disease or cardiovascular disease, or have had heart surgery (bypass, angioplasty, stent implementation, etc.). In other words, a nuclear stress is typically scheduled only after results from previous testing, or prior cardiac events, indicate that further investigation in needed.
A nuclear stress test may also be referenced as a radionuclide test, a myocardial profusion test or a thallium stress test. The term “nuclear” is used because a small amount of a radionuclide is injected in the patient during the test. A radionuclide (thallium, technetium or sestamibi) is a radioactive substance that is employed as a tracer. The tracer will enter the arteries making them definitely visible for gamma imaging. Blockages or partial blockages will not absorb the radionuclide and appear as “cold spots” in the images. Although patients are exposed to a small amount of radiation, this procedure is approved and considered safe.
Prior to the date of your nuclear stress test, you should ask the doctor about taking your prescription medications or over the counter drugs. If you have diabetes or asthma, you will receive special instructions regarding medication. Do not eat or drink for at least four hours before the test. Do not eat or drink anything that has caffeine in it for 24 hours before the test. Chocolate has caffeine and decaffeinated products usually contain trace amounts. Wear comfortable clothes and suitable footwear for using the treadmill.
After you arrive for the test, your blood pressure and heart rate will be measured. You will be given an IV and the tracer will be injected. Approximately 20 minutes later, the first set of images will be taken “at rest.” Then you will have electrodes, for an electrocardiogram, placed on your chest and begin the treadmill exercise. You will begin at a slow pace and gradually increase the pace and incline until your heart rate reaches your targeted level. At this time, you will be given another injection of tracer and walk a few more minutes. Then you will be given a beverage to help enhance the images. Another set of “stress” images will be taken to be compared with the first set. The entire procedure will take two to three hours.
Afterward, you may be provided brief summary of the results. However, Dr. Alonso will evaluate all of the data and images and discuss them with you later. Based on his assessment of your test results, the doctor will recommend a course of action.