What is the test?: An Adenosine Scan, also called myocardial perfusion imaging, is a procedure that lets your doctor look at the flow of blood to the heart muscle.
An Adenosine Scan will help your doctor determine:
- If your heart is receiving enough blood.
- If you have coronary artery disease (CAD).
- If more tests are necessary.
The Adenosine Scan may be done before or after treatment for heart ailments.
How do I prepare for the test?: For this test, certain ingredients that exist in foods and medications - even in tiny amounts - may interfere with the test. These ingredients include caffeine, theophylline and dipyridamole.
For 24 hours before your test, please do not eat or drink any of the foods, and do not take any of the medications, on the list below.
- NO coffee or tea that is brewed, instant, iced or decaffeinated
- NO colas or other soft drinks that contain caffeine, including those labeled "caffeine-free"
- NO chocolates, including candies, frosting, cookies, pies, cocoa and chocolate milk
- NO aspirin products that contain caffeine, such as Anacin and Excedrin
- NO Persantine (dipyridamole)
- NO theophylline or theophylline containing products such as Constant-T, Primatene, Quibron, Slo-Phylline or Theo-Dur
This is only a partial list. Check product labels or ask your pharmacist or doctor to be sure of what products to avoid before your test.
What will happen during the test?: During the test you will be lying on your back. A blood pressure cuff is placed on one arm, and a small intravenous needle (IV) is inserted in your arm. Small round pads are placed on your chest that are attached to an electrocardiograph (ECG) allowing your doctor to monitor your heart rhythm.
Dilating medication is then injected over a period of approximately six minutes. The imaging agent is injected midway through the six minutes. When the injections are over, the doctor will continue to monitor your heart for a couple more minutes.
As the dilating medication is given, you may feel flushed, chest pressure/pain, shortness of breath or some other discomfort. This is perfectly normal, but it is important to tell the doctor just what you are feeling. Usually, these effects disappear by themselves within a minute or two after the injection is over. However, injection of another medication may be required to stop the action of any persistent feelings.
It is possible that you may feel some of the medication's effects for up to 24 hours after the test. If so, please contact your doctor.
Imaging: The next portion of the test involves taking pictures or "imaging" the heart.
During this portion of the test, you will rest on your back, usually with your arms comfortably extended above your head. For approximately the next 45 minutes, images of the blood flow for your heart are taken by a special camera. It's important that you lie still during this procedure to ensure the best possible images. The camera is large, but it doesn't even come in contact with you, and it doesn't hurt or emit any radiation.
You may be asked to return a couple hours later for a second round of images when your heart is "at rest." These images are compared to the images obtained during the first part of the test.
After the test: When your Adenosine scan is complete, your doctor will know more about the blood flow to your heart muscle and your health. He will be able to discuss the test results with you right away.
