Stress Echocardiogram

What is an exercise echocardiogram?

An echocardiogram is a noninvasive (the skin is not pierced) procedure used to assess the heart’s function and structures. An exercise echocardiogram is performed to assess the heart’s response to stress or exercise. During the procedure, a transducer (like a microphone) sends out ultrasonic sound waves at a frequency too high to be heard. When the transducer is placed on the chest at certain locations and angles, the ultrasonic sound waves move through the skin and other body tissues to the heart tissues, where 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 obtained, the person will begin to exercise on a treadmill or stationary bicycle. The doctor will compare the resting echocardiogram with the test done immediately after exercise.

An exercise echocardiogram may use one or more of several special types of echocardiography, as listed below:

• M-mode echocardiography. This, the simplest type of echocardiography, produces an image that is 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, which can indicate a problem with one or more of the heart’s four 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 observed. This enables the doctor to see the various heart structures at work and evaluate them.
• 3-D (three-dimensional) echocardiography. This technique captures three-dimensional views of the heart structures with greater depth 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 determine the appropriate plan of treatment for a person with heart disease.

Other related procedures that may be used to assess the heart include resting or exercise electrocardiogram (ECG or EKG), Holter monitor, signal-averaged ECG, cardiac catheterization, chest X-ray, computed tomography (CT scan) of the chest, electrophysiological studies, magnetic resonance imaging (MRI) of the heart, myocardial perfusion scans, radionuclide angiography, and cardiac CT scan. Please see these procedures for additional information.

Reasons for the procedure

An exercise echocardiogram, obtained after you have exercised on a treadmill or stationary bicycle, may be performed for the following reasons:

• To assess the heart’s general function and structures
• To assess stress or exercise tolerance in patients with known or suspected coronary artery disease
• To determine limits for safe exercise in patients who are entering a cardiac rehabilitation program and/or those who are recovering from a cardiac event, such as a heart attack (myocardial infarction, or MI) or heart surgery
• To evaluate blood pressure levels during exercise
• To evaluate the cardiac status of a patient about to undergo surgery

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, but are not limited to, the following:

• Chest pain
• Severely high blood pressure
• Irregular heartbeats
• Dizziness
• Nausea, and extreme fatigue
• Heart attack (rare)

If you are pregnant or suspect that you may be pregnant, you should notify your health care provider.

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

Certain factors or conditions may interfere with the accuracy of an exercise echocardiogram. These factors include, but are not limited to, the following:

• Smoking or ingesting caffeine within three hours prior to the procedure
• Chronic obstructive pulmonary disease
• Beta-blocking medications may make it difficult to increase the heart rate during the test

Before the procedure:

• Your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
• 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.
• Fasting may be required before the procedure. Your doctor will give you instructions as to how long you should withhold food and/or liquids. In some cases, cigarettes and caffeinated beverages, such as coffee, tea, and cola may be restricted two to three hours before testing.
• If you are pregnant or suspect that you may be pregnant, you should notify your health care provider.
• Notify your doctor of all medications (prescription and over-the-counter) and herbal supplements that you are taking.
• You may be instructed to hold certain medications before the procedure, such as beta-blockers. Your doctor will give you specific instructions regarding medications.
• Notify your doctor if you have a pacemaker.
• Notify your doctor if you have the following conditions: aneurysm, severe hypertension (high blood pressure), severe heart valve disease, severe congestive heart failure, recent heart attack, pericarditis, or severe anemia (low red blood cell count).
• 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 medical condition, your doctor may request other specific preparation.

During the procedure

An exercise echocardiogram may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor’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 you 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 prior to 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 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 oxygenation 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 or doctor.
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 obtain the desired image of your heart.
8. The technologist will move the transducer probe around and apply varying amounts of pressure to obtain 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 initial images have been obtained, you will use the treadmill or bicycle to begin exercising.
11. You will exercise until you have reached your target heart rate (determined by the doctor 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. You should notify the technologist if you feel any chest pain, breathing difficulties, sweating, or heart palpitations.
14. Immediately following exercise, you will lie on the table or bed while a second set of echocardiogram images is obtained.
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.

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 doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.