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There are three types of Nuclear Stress Test performed at West Michigan Heart.
1. Myocardial Perfusion (Exercise Stress) Test
3. Adenosine Stress Test
4. Dobutamine Stress Test
All three tests require the use of a radioactive tracer to produce images of the heart muscle. When combined with stress either through exercise or use of a pharmacological agent, the scan helps determine if the heart muscle is getting the blood supply it needs.
As Coronary Artery Disease (CAD) progresses, the heart muscle may not receive enough blood when under stress (for example, when exercising). This often results in chest pain called Angina Pectoris. On the other hand, there may be no outward physical signs of the disease. If CAD is limiting blood flow to part of your heart, the Nuclear Stress Test may be useful in detecting the presence and significance of CAD.
A Nuclear Stress Test consists of two parts, rest and stress:
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A radioactive tracer will be administered by injection through your IV while you are at rest, and a special camera will take pictures of your heart.
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The radioactive tracer will be administered to you one other time by an IV injection during the stress portion of the test, and additional pictures will be taken of your heart.
This allows the doctor to compare the amount of blood flowing through the heart muscle during stress and at rest.
The amount of radiation you will be exposed to is comparable to that from an X-ray or CAT (CT) scan. The half-life of Cardiolite is 6.02 hours. This means that half of the dose you are given will decay in 6.02 hours.
Generally, the radioactive agent is cleared from your body in 24 hours by natural processes. You won't feel any different after you are injected with the agent. Most patients experience no side effects. Occasionally patients have a metallic taste in their mouth.
Myocardial Perfusion Stress Test
This test is designed to provide information about how your heart performs under stress and about the perfusion or blood flow to the heart muscle. It does not actually look at the arteries of the heart (coronary arteries), but indirectly indicates coronary artery obstruction by detecting reduction in blood flow.
A small intravenous (IV) needle will be inserted into your hand or arm and a small amount of sestamibi, a radioactive imaging substance (NOT A DYE), will be injected. After a 45 minute wait, you will lie under an x-ray camera for a scan of your heart. This will take approximately 20 minutes.
During the second part of the test, your heart is put under stress by asking you to exercise on a treadmill at progressively greater speeds and inclines. Even though you may not be a conditioned athlete, we will ask you to do your best by walking as long as you reasonably can on the treadmill since the better your effort, the more information we can obtain. When you feel you have exercised as much as you can, an additional small amount of the sestamibi imaging substance will be injected into the blood stream through your IV. After another 45 minute wait, you will again be scanned. Normally the imaging substance should circulate to all of the heart muscle. If there is a diminished blood supply in one or more of the arteries that carry blood to the heart muscle, there will be a blank spot in the image of the heart on the scan.
If you are scheduled to see the physician expect an additional 1-1 ½ hours wait, for processing and interpretation. Please allow approximately 4 hours that you will remain in the office for test completion.
Adenosine Myocardial Perfusion Test
Myocardial blood flow imaging is a stress test designed to provide information about how your heart performs during exercise and about the flow of blood (perfusion) to the heart muscle. It does not actually look at the arteries of the heart (coronary arteries), but indirectly indicates coronary artery obstruction by detecting reduction in blood flow.
A small intravenous (IV) needle will be inserted into your hand or arm. An injection of sestamibi, a radioactive imaging substance (NOT A DYE) will be given. There is then a 45 minute wait before scanning. The scan will take approximately 21 minutes while you lay under an xray camera.
During the second part of the test a medication called adenosine will be infused over 6 minutes to increase the blood flow to your heart. A small amount of sestamibi will be injected through the IV at 3 minutes of the 6 minute infusion.
Many people experience common, but short-lived, side effects during the infusion of adenosine including flushing to the face, neck or jaw pain, shortness of breath, coughing, or chest heaviness. This does not mean that anything is wrong. It is just common effects of the medication. Other people do not experience any effects during the infusion while still others state they feel different or strange. Within 2 minutes after the infusion is completed, the side effects are gone as the adenosine rapidly leaves the body.
Normally, the imaging substance should circulate to all of the heart muscle. If there is a diminished blood supply in one or more of the arteries that carry blood to the heart muscle, there will be a blank spot in the image of the heart on the x-ray.
After another 45 minute wait, images will again be obtained. The second scan also takes about 21 minutes.
If you are scheduled to see the physician expect an additional 1 – 1 ½ hours wait, for processing and interpretation. Please allow approximately 4 hours that you will remain in the office for test completion.
Dobutamine Myocardial Perfusion Stress Test
Myocardial blood flow imaging is a stress test designed to provide information about how your heart performs under stress and about the flow of blood to the heart muscle. It does not actually look at the arteries of the heart (coronary arteries), but indirectly indicates coronary artery obstruction by detecting reduction in blood flow.
A small intravenous (IV) needle will be inserted into your hand or arm. A small amount of Sestamibi, a radioactive imaging substance (NOT A DYE), will be injected. After a 45 minute wait, you will lie under an x-ray camera for a scan of your heart. The scan will take approximately 21 minutes.
After the scan you will be moved to a stretcher. Your heart will be put under stress by giving you a medication through the IV called Dobutamine, to increase the rate and force of your heartbeat. You may also notice that your breathing speeds up temporarily. The infusion of Dobutamine takes approximately 12 minutes. At the end of the Dobutamine infusion, you will be given another injection of Sestamibi.
After another 45 minutes wait, you will again be scanned (this takes another 21 minutes). Normally the imaging agents should circulate to all of the heart muscle. If there is a diminished blood supply in one or more of the arteries that carry blood to the heart muscle, there will be a blank spot in the image of the heart on the scan.
If you are scheduled to see the physician expect an additional 60-90 minute wait for processing and interpretation. Please allow approximately 4 hours that you will remain in the office for test completion. How do I prepare for the test?
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Do not eat or drink for 4 hours prior to the test--this includes caffeine! The pictures of your heart are clearer when the stomach is not full. If you are diabetic or need to eat/drink with your medication, get special instructions from your doctor.
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Avoid any strenuous physical activity on the day of the test because you will need to exert yourself maximally if you are doing an exercise test.
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Bring busy material. You will have periods of waiting throughout the test so bring a book, newspaper, knitting, etc. to keep you busy.
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No smoking 4 hours prior to the test. Smoking may interfere with the test results.
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Wear a comfortable two-piece outfit and comfortable shoes. A hospital gown may be provided and men may be asked to take off their shirt. Slacks or shorts are preferred if you are exercising. You should wear comfortable footwear appropriate for brisk exercise if you are doing an exercise test.
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Do not wear oils or lotions before your test. Small sticky patches (electrodes) will need to stick to your chest.
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Do not take the following heart medications on the day of your test unless your physician tells you otherwise or if the medication is needed to treat chest discomfort:
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Isosorbide Dinitrate (for example: Isordil, Sorbitrate)
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Isosorbide Mononitrate (for example: Ismo)
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Nitroglycerin (for example: Deponit, Nitrostat)
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Your physician may also ask you to stop taking other heart medications on the day of your test. If you have any questions about your medications, ask your physician.
NOTE: Do not discontinue any medication without first talking with your physician
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