Norfolk County Cardiologist Association
Cardiac Imaging with Cardiolite and IV Persantine
UNDERSTANDING HEART DISEASE
Your heart is responsible for pumping blood throughout your entire body. The coronary arteries supply blood containing oxygen and other nutrients to the heart muscle. However, these arteries can become blocked by the accumulation of fatty substances (called lipids). This blockage is called atherosclerosis or coronary artery disease (CAD).
The stress exam with Cardiolite is a diagnostic nuclear medicine exam used to determine if the heart muscle is getting the blood supply it needs.
As CAD progresses, the heart muscle may not receive enough blood, especially during times of stress or physical activity. For some people, this will cause chest pain (angina pectoris), breathlessness, and/or fatigue. For others, there may be no symptoms to indicate that blood supply to the heart is not sufficient. However, if CAD goes undetected or untreated, there is the potential for more serious complications to occur, such as a heart attack. But there are risk factors that alert your doctor that you may be at risk for CAD.
RISK FACORS OF CAD
1. Family history
If your doctor suspects that CAD is limiting blood flow to the part or many parts of your heart, an imaging test with Cardiolite may be useful in detecting the presence and extent of CAD. The results of the test will help your doctor determine the best possible treatment options for you - options that will reduce your risk of a heart attack.
There are several reasons for your doctor to recommend an imaging test with Cardiolite.
REASONS YOUR DOCTOR MAY WANT TO PERFORM THIS TEST
1. If you have chronic chest pain or angina - images provide valuable information as to why you may be experiencing chest pain.
What's more, this test reliably identifies CAD in women, which may lead to earlier diagnosis and treatment (See Special Information for Women on pages 18-19).
This brochure is intended to answer some of the questions you may have about eh imaging test with Cardiolite. After reading this brochure, be sure to ask your doctor about anything that you still don't understand or would like more information on.
CARDIAC IMAGING WITH CARDIOLITE
Cardiac imaging allows your doctor to assess blood flow to your heart. Typically, two sets of images are taken:
1. At rest (lying down) - The images taken at rest allow your doctor to see how your heart functions under normal conditions.
Images, taken at many angles, provide a complete picture of your heart.
Images are obtained using a special camera called a gamma camera. This camera takes pictures of your heart and transmits them into a computer, where your doctor can see how the walls of your heart move.
HOW THE TEST IS PERFORMED
To start, a nuclear medicine technologist will insert an intravenous (IV) line into your arm, which will be used later to administer Cardiolite, the imaging agent. Additionally, several small wires (electrodes) will be placed on your chest. These electrodes are attached to an electrocardiograph (ECG) machine that allows your doctor to monitor your heart rate and rhythm while you exercise.
THE STRESS TEST
For the stress part of the test, you will be asked to exercise either by walking in a treadmill or by riding a stationary bicycle. As you continue to exercise, your heart rate and blood pressure will increase. Expect to exercise for about 10 minutes. This will ensure that your heart is working to its full capacity. If, however, you experience any unusual symptoms, such as lightheadedness, tell the doctor or technologist immediately. Adjustments will be made to the exercise test depending on your symptoms, blood pressure, ECG, and/or degree of fatigue. To increase the accuracy of the test and to enhance the quality of the images, it is critical that you exercise for as long as you are able. When you reach your maximal level of exertion, you will be injected with Cardiolite and asked to continue to exercise for an additional minute or two. This imaging agent circulate throughout the body and settles in your heart muscle.
If you are unable to perform physical exercise to the needed levels of exertion, your doctor may opt to use a drug (pharmacologic stress agent) such as I. V. Persantine.
This type of drug simulates the effects of exercise by expanding the coronary arteries, which increases blood flow to the heart. Once I.V. Persantine takes effect, Cardiolite can be administered, and images can be taken. For more information about pharmacologic stress, please see the section on I.V. Persantine on pages 12-17.
HOW IMAGES ARE OBTAINED
In order to obtain the images (both rest and stress), the technologist will ask you to lie flat on a table. The camera, which is located above your body, will be moved to various positions around your chest. It will take about 15-30 minutes to obtain all the needed images. During this time, it is important that you remain very still, as any sudden movements will blur the images.
Following completion of the exam, a doctor who specializes in nuclear medicine will submit a report to your doctor. From here, you and your doctor will discuss the test results and the course of action that needs to be taken.
PREPARING FOR THE TEST
To keep you comfortable throughout the test and to ensure the best possible pictures, you may be asked:
1. Not to eat or drink 3-4 hours prior to the test - a full stomach may interfere with the quality of the images.
On the day of the test, you may be asked to sign a consent form that states that you understand the test. Please take the time to read the form carefully, and do not hesitate to ask questions about the procedure before it begins.
An imaging test with Cardiolite (or other cardiac imaging agent) involves a small amount of radioactivity. The amount of radiation you will be exposed to is comparable to that from an X-ray or CAT (CT) scan.
1. If you are pregnant, suspect that you are pregnant, or are nursing, please tell your doctor before undergoing this procedure.
As mentioned earlier, part of the imaging test with Cardiolite requires that you exercise to a maximal level of exertion. If you are unable to perform physical exercise, your doctor may choose to use an agent such as I.V. Persantine, to expand the coronary arteries to increase blood flow. This is similar to what would happen during vigorous exercise.
THE I.V. PERSANTINE STRESS STUDY
Electrodes, connected to an ECG monitor, will be placed on your chest. This allows the doctor to monitor the heart rate changes that will occur once I. V. Persantine has been injected. You will also have an IV line placed in your arm that will be used to administer I.V. Persantine and the imaging agent.
The administration of I.V. Persantine is relatively slow - it will take up to 4 minutes for the full dose to be given to you. This will make the onset of stress more comfortable and give you an opportunity to adjust to the changes that are occurring. If should feel as though you have been exercising vigorously. If you have any unusual sensations during or immediately following the administration of I.V. Persantine, tell your doctor at once.
Even though you are undergoing stress via pharmacologic means, your doctor may ask you to perform low-level exercise such as using a handgrip, waling in place, or some other small movement. These simple tasks will make the onset of stress more comfortable, possibly reduce side effects, and improve the quality of the images.
Once the I.V. Persantine has taken effect, the imaging agent will be administered. Then images will be taken.
I.V. Persantine ahs an established safety record. However, there may be some side effects that can easily be reversed. Potential side effects include chest pain, headache, dizziness, nausea, and flushing. Your doctor will talk to you about this in greater detail. If you have any unusual feelings, be sure to mention them to your doctor during the test.
PREPARING FOR I.V. PERSANTINE
It will be important for you to check with your doctor about any restriction in diet or the use of certain medications prior to receiving I.V. Persantine. Some doctors ask that you not eat or drink anything containing caffeine for the 4-6 hours preceding the test.
Here is the partial list of foods and medications that should be avoided before the test. Be sure to ask your doctor for a more complete list that addresses your dietary and medication-taking requirements.
Coffee and tea beverages (including caffeine-free)
MEDICATIONS (Prescription and Nonprescription)
Anacin, Cafergot (all forms), Darvon Compound, Excedrin, Fiorinal, NoDoz,
If you are taking any medications for asthma, such as theophylline or aminophylline, be sure to tell your doctor. It may be important to stop taking these medications for 36-48 hours before the test. Here is a partial list of medications that contain theophylline.
Aerolat, Bronkodyl, Constant-T, Elixophylline SR, Wuibro-T/SR, Respbid, Slo-Bid Gyrocps, Dlo-Phyllin Gyrocaps, Sustaire, Theo-24, Theo-Dur Sprinkle, Theo-Dur, Theobid Duracap, Theochron, theoclear L.A., Theolair-SR, Theophylline S.R., Theospan Jr. Duracap, Theospan-SR, Theovent Long-Acting, Uniphyl.
Be certain to tell the doctor administering I.V. Persantine if you:
1. Have any known allergy to theophylline or dipyridamole.
If you are currently taking dipyridamole or Persantine tablets you may continue to do so, as they will have no effect on your test. You may also continue to take other heart medications that your doctor ahs prescribed. It is important that your doctor know all medications that you are taking.
SPECIAL INFORMATION FOR WOMEN
More and more attention is being given to the special needs of detecting heart disease in women. This is very important; as women don't always respond the same way to tests and procedures as do men. There are many methods being used to detect heart disease in women. And, of course, some tests and agents work better than others.
CARDIAC IMAGING FOR WOMEN
Because the camera is outside of your body and must "see through" your chest into your heart, there is the potential for your left breast to partially cover the heart and cast "shadows" or artifacts over the heart. (If you have breast implants, tell your doctor; they may also cause artifacts). Artifacts distort the actual look of the heart and increase the potential for an inaccurate (false-positive) diagnosis. False-positive test shows disease when none is present.
False-positive results may be reduced by using an agent such as Cardiolite. This helps ensure that images will provide a more detailed picture of your heart. Images without shadows or artifacts are easier for your doctor to read and allow your doctor to make a more reliable decision about he health of your heart.
What's more, if you are unable to exercise to adequate levels of exertion, pharmacologic stress agents such as I.V. Persantine can be used to optimize the stress procedure and help improve imaging results.
If you would like to find out more about heart disease, what your risk factors are, how you can reduce your risk factors, what types of symptoms women experience, and about methods of detection that are best suited for women, please call The Difference in a Woman's Heart infoline at 1-800-231-1973
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