Nuclear Medicine Stress Test

What is a Nuclear Stress Test

A nuclear stress test lets doctors see pictures of your heart while you are resting and shortly after you have exercised. The test can give information about the size of the heart's chambers, how well the heart is pumping blood, and whether the heart has any damaged or dead muscle. Nuclear stress tests can also give doctors information about your arteries and whether they might be narrowed or blocked because of coronary artery disease.

How does it work?

A technologist will give you a small amount of a radioactive substance just before the end of the exercise part of the test. This radioactive substance is not harmful to your body or your organs. The results of the nuclear stress test can show doctors if the heart is not working properly while you are resting, exercising, or both.
If the test shows that blood flow is normal while you are resting but not normal while you are exercising, then doctors know that your blood flow to your heart is not adequate during times of stress.
The heart normally pumps more blood during times of physical exertion. If the test results are not normal during both parts of the test (rest and exercise), part of your heart is permanently deprived of blood or is scarred. If doctors cannot see the radioactive substance in one part of your heart, it probably means that section of heart muscle has died, either because of a previous heart attack or because the coronary arteries supplying blood to that area of the heart are blocked.

What To Expect During Stress Testing

• A Nuclear Medicine Stress Test is similar to a standard treadmill stress test, but provides the doctor with additional information by using an isotope to evaluate coronary blood flow.

• An intravenous (IV) line will be started in order to inject a very small dose of the isotope at the peak of exercise. The isotope is not harmful to the patient or the heart.

• Electrodes are placed on the chest to record an electrocardiogram (EKG), which monitors the electrical activity of the heart.

• The doctor will have you exercise on a treadmill, gradually increasing the speed and incline.

• If you can?¢‚Ǩ‚Ñ¢t exercise, a technician will inject a medicine into a vein in your arm or hand. This medicine will increase the flow of blood through the coronary arteries and/or make your heart beat faster, as would exercise. This results in your heart working harder, so the stress test can be performed. The medicine may make you flushed and anxious, but the effects disappear as soon as the test is over. The medicine may also give you a headache.

• During the exercise portion of the test, the doctor will be looking for changes in the EKG pattern and any symptoms that you may experience.

• The test will be stopped if you become too tired, have certain symptoms, or when the doctor feels the information needed has been gathered.

• After the exercise portion of the test a special camera will take pictures of the heart, requiring you to lie flat with both arms supported above the head. A second set of images will be taken shortly afterward to complete the test and further evaluate the blood supply to the heart