What is an exercise echocardiogram?

An echocardiogram is a noninvasive (the skin is not pierced) test used to see how well the heart is working. An exercise echocardiogram is done to assess the heart's response to stress or exercise and compare the results to when the heart is at rest. During the procedure, a transducer (like a microphone) sends out high-frequency sound waves. When the transducer is placed on the chest at certain locations and angles, the sound waves move through the skin and other body tissues to the heart. There the waves bounce or "echo" off of the heart structures. The transducer picks up the reflected waves and sends them to a computer. The computer displays the echoes as images of the heart walls and valves.

After the resting echocardiogram images have been taken, you will start to exercise on a treadmill or stationary bicycle. You will exercise until your heart rate reaches a goal for your age or to the point you start having symptoms that limit your ability to keep exercising. The doctor will compare the resting echocardiogram with the test done right after exercise.

An exercise echocardiogram may use one or more of these methods of echocardiography:

• M-mode echocardiography. This is the simplest type of echocardiography. It produces an image similar to a tracing rather than an actual picture of heart structures. M-mode echo is useful for measuring heart structures, such as the heart's pumping chambers, the size of the heart itself, and the thickness of the heart walls.

• Doppler echocardiography. This Doppler technique is used to measure and assess the flow of blood through the heart's chambers and valves. The amount of blood pumped out with each beat is an indication of the heart's functioning. Also, Doppler can detect abnormal blood flow within the heart. This can mean there is a problem with one or more of the heart's valves, or with the heart's walls.

• Color Doppler. Color Doppler is an enhanced form of Doppler echocardiography. With color Doppler, different colors are used to designate the direction of blood flow. This simplifies the interpretation of the Doppler technique.

• 2-D (two-dimensional) echocardiography. This technique is used to visualize the actual structures and motion of the heart structures. A 2-D echo view appears cone-shaped on the monitor, and the real-time motion of the heart's structures can be seen. This lets the healthcare provider see the various heart structures at work and evaluate them.

• 3-D (three-dimensional) echocardiography. This method captures three-dimensional views of the heart structures with greater detail than 2-D echo. The live or "real time" images allow for a more accurate assessment of heart function by using measurements taken while the heart is beating. 3-D echo shows enhanced views of the heart's anatomy and can be used to plan treatment. 

Reasons for the procedure

An exercise echocardiogram may be done for these reasons:

• To check for coronary artery disease

• To assess how well the heart works and if the structures are normal

• To check the heart to be sure exercise is safe for someone entering a cardiac rehab program or someone who is recovering from a heart attack (myocardial infarction, or MI) or heart surgery

• To test blood pressure levels during exercises

• To see the cardiac status of a person about to have surgery

• To evaluate symptoms of shortness of breath, or trouble breathing that comes on with exercise

There may be other reasons for your doctor to recommend an exercise echocardiogram.

Risks of the procedure

Possible risks associated with an exercise echocardiogram include:

• Chest pain

• Severely high blood pressure

• Irregular heartbeats

• Dizziness, lightheadedness, or feeling like you are going to faint

• Nausea, and extreme fatigue

• Heart attack (rare)

There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your healthcare provider before the procedure.

Certain things may interfere with the accuracy of an exercise echocardiogram, such as:

• Smoking or ingesting caffeine within 3 hours before the procedure

• Chronic obstructive pulmonary disease (COPD)

• Beta-blocker or calcium blocker medicines may make it hard to increase the heart rate during the test

Before the procedure

• Your healthcare provider will explain the procedure to you and you can ask questions.

• You will be asked to sign a consent form that gives your permission to do the test. Read the form carefully and ask questions if something is not clear.

• You may need to fast before the test. Your healthcare provider will give you instructions as to how long you should withhold food and liquids. In some cases, cigarettes and caffeinated beverages, such as coffee, tea, and cola may be restricted 2 to 3 hours before testing.

• If you are pregnant or think you could be, tell healthcare provider.

• Tell your doctor of all medicines (prescription and over-the-counter) and herbal supplements that you are taking.

• You may be told to hold certain medicines before the procedure, such as beta-blockers. Your provider will give you specific instructions about medicines.

• Tell your doctor if you have a pacemaker.

• Tell your doctor if you have the following conditions: aneurysm, severe high blood pressure, severe heart valve disease, severe heart failure, recent heart attack, pericarditis, or severe anemia (low red blood cell count), or chronic lung diseases that affect your breathing with exercise.

• Plan to wear loose, comfortable clothing for the exercise portion of the test, as well as a pair of comfortable walking shoes.

• Based on your condition, your provider may request other specific preparation.

During the procedure

An exercise echocardiogram may be done on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your healthcare provider's practices.

Generally, an exercise echocardiogram follows this process:

1. You will be asked to remove any jewelry or other objects that may interfere with the procedure. You may wear your glasses, dentures, or hearing aids if you use any of these.

2. You will be asked to remove clothing from the waist up and will be given a gown to wear.

3. You will be asked to empty your bladder before the procedure.

4. You will lie on your left side for the first set of echo images. A pillow or wedge will be placed behind your back for support.

5. You will be connected to an electrocardiogram (ECG) monitor that records the electrical activity of the heart and monitors the heart during the procedure using small, adhesive electrodes. Your vital signs (heart rate, blood pressure, breathing rate, and oxygen level) will be monitored during the procedure. The ECG tracing that will record the electrical activity of the heart will be compared to the images displayed on the echocardiogram monitor.

6. The room will be darkened so that the images on the echocardiogram monitor can be viewed by the technologist.

7. The technologist will place warmed gel on your chest and then place the transducer probe on the gel. You will feel a slight pressure as the technologist positions the transducer to get the desired image of your heart.

8. The technologist will move the transducer probe around and apply varying amounts of pressure to get images of different locations and structures of your heart. The amount of pressure behind the probe should not be uncomfortable. If it does make you uncomfortable, however, let the technologist know.

9. The different echocardiogram techniques described above (M-mode, 2-D, 3-D, Doppler, and color Doppler) may be used. You will not be aware of the different techniques except that during the Doppler or color Doppler, you may hear a "whoosh-whoosh" sound, which is the sound of the blood moving through the heart.

10. Once the echocardiogram first set of resting images have been taken, you will start exercising on the treadmill or stationary bike.

11. You will exercise until you have reached your target heart rate (determined by the healthcare provider based on your age and physical condition), or until you are unable to continue due to chest pain, leg pain, severe shortness of breath, or severe fatigue.

12. Once you have reached your target heart rate, you may continue to exercise as tolerated, as exercise duration is an important component of the stress test result.

13. Tell the technologist if you feel any chest pain, breathing difficulties, excessive sweating, or heart palpitations.

14. Immediately after exercise, you will lie on the table or bed while a second set of echocardiogram images is taken.

15. After the procedure has been completed, the technologist will wipe the gel from your chest and remove the ECG electrode pads. You may then put on your clothes.

16. Ask your provider when and how you will get the results of your stress echocardiogram.

After the procedure

You may resume your usual diet and activities unless your doctor advises you differently.

Generally, there is no special type of care following an exercise echocardiogram. However, your healthcare provider may give you other instructions after the procedure, depending on your particular situation.