Echocardiography uses sound waves to produce an image of the heart and to see how it is functioning. Stress echocardiography (or stress echo) lets doctors see the wall motion of the heart's pumping chambers before and after exercise. The test can show if certain areas of the heart muscle are not getting enough oxygen-rich blood.

If your doctor wants you to have a stress echocardiogram, you will have the same test as exercise stress testing, except that when your heart rate reaches a certain number you will be asked to step off of the treadmill or stationary bike and lie down.

For patients who are too sick to exercise, doctors can give them a drug that has the same effect on the body that exercise does. Some examples of the drugs that may be given are dobutamine or adenosine. You may hear this type of test called a dobutamine stress echo.

How does it work?

Echocardiography uses high-frequency sound waves (also called ultrasound) that can provide a moving picture of your heart. The sound waves are delivered through the body with a device called a transducer. The sound waves bounce off of the heart and return to the transducer as echoes. The echoes are converted into images on a television monitor to produce a one-, two-, or three-dimensional picture of your heart.

What should I expect?

After your heart has reached a certain rate during exercise on a treadmill or stationary bike, you will be asked to lie down on an examination table. Next, the technician will put a thick gel on your chest. The gel may feel cold, but it does not harm your skin. Then the technician will use the transducer to send and receive the sound waves.

The transducer will be placed directly on your chest, above your heart. The technician will press firmly as he or she moves the transducer across your chest. You may be asked to breathe in or out or to hold your breath briefly during the test. For most of the test, you will lie still.

Most stress echo tests take about 45 minutes, but a dobutamine stress echo takes longer.