These tests are used to evaluate patients for blockages in the arteries to the heart by visualizing the pumping function of the heart during non-exercise stress. Cardiac ultrasound is used to image the function of the heart and medicines (dobutamine or dopamine) are used to stress the heart. During stress, all the regions of the heart should pump more forcefully. Cardiac ultrasound can detect the presence of blockages in the arteries to the heart if a region of the heart is seen to have reduced pumping function during stress. The Krannert Institute and Indiana University introduced the technique of dobutamine stress echocardiography in the United States over 17 years ago.

Reasons for Testing

In most cases your physician will have referred you for this test because he or she felt that you cannot adequately perform treadmill or bicycle exercise because of some physical limitation. In some other instances non-exercise stress testing may provide information that a standard exercise stress test does not provide. Dobutamine and dopamine, the medicines used to stress the heart, are similar to adrenalin, the substance produced in your body when you exercise that causes an increase in your pulse and blood pressure. These tests are frequently done not only to evaluate for blockages in the arteries to your heart but also to see if heart will adequately cope with the stress of a major non-heart related surgical procedure.

Contraindications & Preparations for Testing

There are few contraindications to undergoing these tests. If you have had a previous adverse reaction to dobutamine or dopamine you should let the staff know before testing is scheduled. If you have had a recent change in symptoms, such as the recent onset of chest pain you should tell the staff when you arrive for your test. The stress testing medicine that you receive (dobutamine or dopamine) will be selected by the staff and this may depend on your medical history and blood pressure. You should take your usual medicines the day of the test. However, you may be asked not to take certain medicines, like beta-blockers, before testing. Non-exercise stress testing has equivalent safety to exercise testing with the chance of serious complications being about 1 in 1000 tests performed. You should not eat solid food for 4 hours prior to testing.

Since the Krannert Institute is a leader in development and refinement of non-exercise stress testing you may be asked to voluntarily participate in research related to these tests.

Description of Procedure

On arrival to the stress laboratory you will be asked to answer some general questions about health conditions you have, your symptoms, and what medicines you are currently taking.

A small catheter, a thin hollow tube, will be inserted in a vein which will be used to give the stress testing medicine. A blood pressure cuff will also be placed.

You will have small adhesive patches placed on your chest which will be used to monitor the electrical activity of your heart during the test.

A cardiac ultrasound study will be performed before the stress testing medicine is administered to assess the pumping function of the heart at rest.

The stress testing medicine will then be given intravenously over an 6 to 20 minute period to increase your heart rate and blood pressure to a desired level of stress. The test will be monitored by a nurse or physician trained in performance of stress tests, along with other personnel who perform cardiac ultrasound and electrocardiogram monitoring.

Common sensations during the test include the feeling that your heart is beating harder, feeling of warmth, skin tingling, dry mouth, and mild nausea. If you develop uncomfortable side effects you are asked to let the staff know and the time of the test will be adjusted to minimize any discomfort.

In some instances, additional medicines will be given to speed up the response of your heart, to reverse the effects of stress once the test is completed, or to treat side effects of the test.

Cardiac ultrasound images will be obtained at various times during the test.

Following achievement of the desired level of stress, the stress testing medication will be discontinued and you may be given a medicine to rapidly reverse the effects of stress.

You will be monitored in the stress testing area for 6 or more minutes after the test is completed. If you are not having blood work or another test, such as nuclear imaging, the intravenous catheter will be removed.

After testing

There are no specific precautions that need to be taken after testing except for any warnings or recommendations about your symptoms that your referring physician has made to you earlier. In rare instances, patients have a residual sensitivity to bright light for an hour or so following testing. In most instances the results of your test will be available by the morning following the test. Your referring physician will receive a printed copy of the test and if he/she has access to the Indiana University Health network system they will be able to look up the results within minutes of the official interpretation. If you have another physician that you would like to receive a report please tell the staff at the time you have the test.