Dobutamine Stress Echocardiogram What is a Dobutamine Stress Echo? A dobutamine stress echocardiogram ("echo") is a test that combines an ultrasound study of the heart with a drug-induced stress test. The test allows doctors to learn how the heart functions when it is made to work harder. Generally, a stress test is performed while patients walk on a treadmill or ride a stationary bicycle. For patients who are unable to exercise adequately (for a variety of reasons) the test may be done after injection of dobutamine, a drug that produces an effect on the heart similar to exercise. The dobutamine stress echo is especially useful in diagnosing coronary artery disease, the presence of blockages in the coronary arteries (the vessels that supply oxygen-rich blood to the heart muscle). What does it show? During a echocardiogram, a small device called a transducer is held against the chest. The transducer sends ultrasound waves that reflect (echo) off the various parts of the heart. The echoes are converted into moving images of the heart. These images are displayed on a television screen and are digitally recorded. An echocardiogram is first done while your heart is "resting." Dobutamine is then infused (injected slowly) into a vein in your arm. This potent drug causes your heart to pump faster and harder. Additional echo images are then obtained during and after the infusion of dobutamine. Doctors then compare the images. Normally, all areas of the heart muscle pump more vigorously during stress. If an area of the heart does not pump as it should during the infusion, this often indicates that it is not receiving enough blood because of a blocked or narrowed artery. The dobutamine stress echo shows doctors which areas of the heart muscle do not receive an adequate blood supply. However, it does not provide images of the actual coronary arteries. If your doctor suspects blocked or narrowed arteries, additional tests may be recommended. (See 64-Slice CT) Preparing for the test Do not eat or drink 4 hours prior to the test. This will help prevent the possibility of nausea, which may accompany the infusion of dobutamine. If you are currently taking heart medications (especially beta blockers), check with your doctor. He or she may ask you to stop them a day or two before the test. This can help get more accurate test results. Before the test, you'll be given an explanation of the test and you'll be asked to sign a consent form. Feel free to ask any questions about the procedure. An intravenous(IV) line will be inserted into a vein in your arm, to allow injection of dobutamine. Several electrodes (small sticky patches) will be placed on your chest to obtain ECG (electrocardiogram), a recording of your heart's electrical activity.