Exercise Stress Testing
What is an Exercise Echocardiogram?
An exercise echocardiogram, also known as a stress echocardiogram, is a
test that combines an ultrasound study of the heart with an exercise test.
The test allows doctors to learn how the heart functions when it is made to
The exercise echocardiogram 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).
Is the Exercise Echocardiogram Safe?
The exercise test is generally safe. A small amount of risk does exist
since exercise stresses the heart. Extremely rare complications include
abnormal heart rhythms and a heart attack. Experienced personnel are
available to handle any emergency.
What Does It Show?
An echocardiogram works very much like sonar. Ultrasound waves are
transmitted into the chest and the reflection of these waves off the various
parts of the heart is analyzed by sophisticated equipment.
A transducer, which is a small microphone-like device, is held against the
chest. The transducer sends and receives the ultrasound waves. By moving the
transducer to various positions on the chest, different structures of the
heart may be analyzed.
A computer assembles the reflected ultrasound waves to create an image of
the heart. These images appear on a television screen. The images may be
recorded on videotape or printed on paper for review by the cardiologist.
To provide a baseline of information, an echocardiogram is first done
while the patient is at rest. Then, a second echocardiogram is obtained
during or immediately after an exercise test using a treadmill.
The images of the heart at rest and during exercise (under stress) are
compared. Normally, all areas of the heart muscle pump more vigorously during
exercise. If an area of the heart muscle does not pump, as it should during
exercise, this often indicates that it is not receiving a sufficient flow of
oxygen-rich blood because of a blocked or narrowed coronary artery.
Although an exercise echocardiogram indicates regions of the heart that
may be affected by reduced blood flow through the coronary arteries, it does
not provide images of the actual coronary arteries. If blocked or narrowed
coronary arteries are suspected, your doctor may recommend additional
Preparing For A Test
- Do not eat or drink 3 hours prior to the test. This will prevent
the possibility of nausea, which may accompany vigorous exercise after
eating. If you are diabetic and take medications for diabetes, get special
instructions from your doctor.
- If you are currently taking any heart medications, check with your
doctor. You may be asked to stop certain medications a day or two before
the test. This can help get more accurate test results.
- Wear loose, comfortable clothing that is suitable for exercise. Men
usually don't wear a shirt during the test, and women generally wear a bra
and a lightweight blouse or a hospital gown. You should also wear comfortable
walking shoes or sneakers.
- Before the test, you will be given an explanation of the test and asked
to sign a consent form. Feel free to ask any questions about the
- Several areas on your chest and shoulders will be cleansed with
alcohol and an abrasive lotion, to prepare the skin for the electrodes. Men
may need to have areas of their chest shaved, to ensure that the electrodes
stay in place.
What Happens During the Test?
The echocardiogram can be performed in the doctor's office or at the
hospital. No special preparation is necessary for this test. If you are
scheduled for an exercise echocardiogram, however, you will be given special
You will be asked to remove clothing above the waist, and put on a hospital
gown or a sheet to help keep you warm and comfortable. You will then lie on
an examination table.
Electrodes (small sticky patches) and wires will be attached to your chest
and shoulders to record your electrocardiogram (ECG or EKG). The ECG shows
your heart's electrical activity during the test.
Next, you will lie on your back or on your left side. To improve the quality
of the pictures, a colorless gel is applied to the area of the chest where
the transducer will be placed.
A technician moves the transducer over the chest, to obtain different views
of the heart. He or she may ask you to change positions. You may also be
asked to breathe slowly or hold your breath, in order to get a better
picture. A thorough examination usually takes from 20 minutes to an hour,
depending on the number of views and whether the Doppler echo is used.
What Happens During the Test?
You will be asked to lie on a hospital bed or examination table. To improve
the quality of the pictures, a colorless gel is applied to the area of the
chest where the transducer will be placed.
A technician moves the transducer to various places over the left side of
your chest. Pictures of your heart at rest are recorded on videotape.
The exercise portion of the test can be performed in the doctor's office or
at the hospital. A trained technician will place several electrodes (small
sticky patches) on your chest and shoulders to allow recording of the ECG
during exercise. Wires link the electrodes to an ECG machine. A cuff will be
applied to your arm to monitor your blood pressure during the test.
You will be shown how to step onto the treadmill and how to use the
support railings to maintain your balance. The treadmill starts slowly, and
then the speed and incline are increased gradually.
Your blood pressure will be checked every few minutes, and the ECG will
be carefully watched for abnormal changes. You will be instructed to report
any symptoms, such as chest pain, shortness of breath, leg fatigue, or
The test may end when you become too tired to continue or when you
experience significant symptoms. Other times, the test may be stopped when
you reach your peak heart rate or when your ECG shows abnormal changes.
After the exercise portion of the test is over, you will be helped to a
chair or a bed. Your blood pressure and ECG will be monitored while you
recover. The technician will remove the electrodes and cleanse the electrode
sites. The test typically takes between 45 minutes to one hour, which
includes preparation for the test, the exercise portion, and the recovery
You will be helped back to the examination table. The technician records a
second set of images immediately after you finish exercising.
Doctors then compare the two sets of images (before and after exercise) side
by side to see how your heart responds to the stress of exercise.
Typically, the doctor will review the images at a later time and prepare a
report detailing his findings. This may take several days before the
completed report is ready.