| L. Allen Kindman, MD Evelyn Parham, ANP Megan Andrews ANP |
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Adenosine Cardiolite Scan What is an Adenosine Cardiolite Scan?Cardiologists use “Stress Tests” of different types to determine how well the heart functions when it is made to work harder. You may be more familiar with an Exercise Tolerance, or Treadmill test, but for patients unable to exercise adequately (for a variety of reasons), the test may be done after the injection of a drug, Adenosine, that produces an effect on the heart similar to exercise. The Adenosine Cardiolite Scan is a test that combines a drug-induced stress test with a nuclear medicine scan of the heart. The Cardiolite Scan is a test that uses a radioactive substance (known as a tracer) to produce images of the heart. Preparing for the TestDo not eat or drink anything three hours prior to your scheduled arrival time. Patients scheduled in the morning should not eat breakfast. Patients scheduled for afternoons should not eat lunch. Carefully follow any instructions regarding medications. In some cases, your doctor may want you to stop some of the medications for a day or two prior to the test. DO NOT CONSUME ANY CAFFEINE FOR 24 HOURS BEFORE THE TEST! This includes coffee, tea, colas, and chocolate, as well as any over the counter or prescription medications that contain caffeine. Caffeine can interfere with the action of the drug used in the test. If you take any medications containing theophylline, you may be asked to stop them 2 or 3 days before the test. Like caffeine, these drugs can interfere with the action of the Adenosine used to stress the heart, resulting in an inaccurate test. Please inform your doctor if you have a history of asthma or other chronic lung disease. In such a case, this test could cause severe breathing problems. If you are taking medications for diabetes, please let your doctor know. You may need to make adjustments in your medication dosages that day. You should arrange for someone to accompany you to our office. You may find that you would prefer not to drive home afterwards, as the test can be tiring. Where does the test take place?The Adenosine Cardiolite Scan is conducted in our office. What happens during the test?First of all, you should be aware that this test is conducted in two parts and that you should plan to be at our office approximately 3 ˝ hours. When you arrive, the technician will review the procedure with you. Then the technician will inject the Cardiolite into a vein in your arm. Cardiolite is a radioactive substance that will produce the images of your heart. The Cardiolite travels in the bloodstream and is picked up by the heart muscle cells. About 45 minutes after this injection, you will be asked to sit in a special chair while the camera “scans”, or takes pictures of your heart. This takes about 25 minutes to complete. You are then finished with the “resting” phase of the scan, meaning the camera has taken pictures of your heart while it is at rest. After this part of the test you will be given a small snack. This helps your body excrete the Cardiolite. About three hours later, you will be prepared for the stress portion of the scan. The stress portion of the scan is conducted by your doctor along with a technician who has been trained to assist him with these procedures. First you will be connected to an EKG machine that will record the activity of your heart during the procedure. You will also have a blood pressure cuff placed on your arm to monitor your blood pressure at frequent intervals. You may also have a device called a Pulse Oximeter placed on one of your fingers. This is used to monitor the amount of oxygen in your blood. After these preparations have been completed, the technician will start an intravenous solution in your arm. Initially, only a saline solution will be administered, but this IV will be used to administer the Adenosine and the next dose of Cardiolite. This step of the procedure is the actual “stress” portion of the test. To accomplish this, you are given a dose of Adenosine that has been calculated for your body weight. The medication is infused through the IV over a period of six minutes. Three minutes into the infusion, the technician injects the Cardiolite. There are some side effects you may experience from the Adenosine. These include flushing, headache, lightheadedness, dizziness, nervousness, and GI discomfort. The body metabolizes Adenosine very rapidly, so any side effects you may have will be brief in duration. The effects of the Adenosine are twofold: first of all, it dilates (widens) the arteries in your heart, allowing increased blood flow to the heart muscle. Arteries that are blocked or narrowed cannot dilate as much as normal arteries. As a result, blood flows mostly to areas supplied by normal arteries. The second effect of the Adenosine is to speed the heart rate up to mimic the effect of vigorous exercise. After the Adenosine and Cardiolite injections are complete, you will be given another snack, or you can eat something such as a sandwich brought from home. You then return to the scanner for approximately 25 minutes while the camera takes more pictures of your heart. When the scan is complete, you will be allowed to go home. What does the test show? The Cardiolite tracer travels in the bloodstream to the heart, through the coronary arteries, and is picked up by the cells in the heart muscle. Areas of the heart with a normal blood supply pick up this tracer almost immediately. Areas with abnormal blood flow pick up the tracer very slowly, or in some cases, not at all. The tracer gives off a small amount of radiation that is detected by the scanning camera. A computer processes the information and produces images of the radioactivity in the various parts of the heart. If an area of the heart receives less blood than the rest of the heart, it will pick up less radioactivity and show up as a lighter area, called a “defect”. The reason for getting two sets of images- one at rest and one under stress- is that it allows your doctor and the radiologists to differentiate between areas that temporarily do not receive enough blood, and areas that are permanently damaged, such as from a previous heart attack. Is the Adenosine Cardiolite Scan safe?The radiation exposure during the Cardiolite Scan is very small, and the doses used are safe. However, if you are pregnant, suspect you may be pregnant, or are a nursing mother, please discuss this with your doctor. The Adenosine test is generally safe. There is some potential risk involved, because of the stress on the heart, but the incidence of complications from the test is quite low. Possible complications include: abnormal blood pressure and abnormal heart rhythms requiring electrical shock to restore normal rhythm. More serious complications are extremely rare. Death from stress tests occurs in less than 1 in 10,000 patients. When will I get the results from my test?The results of the Adenosine Scan are interpreted in two parts. Your doctor interprets the EKG response of the heart to the stress. Dr. Kindman and a radiologist who specializes in the interpretation of Nuclear Scans review the films from the scan. The results of this interpretation are usually available in 2-3 days. Your doctor reviews the report from the radiologist and correlates this information with his interpretation to develop a final report. You will be notified by your doctor's office when all the test results are in. Again, this is usually only a matter of a few days. Your doctor will discuss this information with you, and will be very happy to answer any questions you may have. Please feel free to voice your questions and concerns. If, after you and your family review this information, you have any other questions/concerns, please do not hesitate to contact our office at: Oxford Patients: (919) 603-1665 |
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