Stress Echocardiogram

(Also known as: stress echo)

Purpose

A stress echocardiogram is a test to determine how well the heart functions under the stress of exercise. In some cases, exercise stress may be simulated with the use of a drug (dobutamine). The test helps to diagnose the presence or absence of coronary artery disease (blockage of the arteries that supply the heart with oxygen). An echocardiogram is performed before exercise, immediately after exercise, and then again five to seven minutes after the cessation of exercise.

Stress echocardiograms are conducted in the Cardiac Diagnostic Centre (H1) of the University of Ottawa Heart Institute.

Description

1. The technician explains the procedure, takes a brief medical history, and asks the patient to provide informed consent. This is required before the test can proceed.
2. Ten adhesive electrodes are applied to the chest area after the sites have been cleaned with alcohol, shaved (if necessary), and mild abrasion applied.
3. The patient lies on his or her left side while the sonographer takes several resting echo views of the heart. This is done by placing gel on a small plastic probe and positioning it on the left side of the patient’s chest. In order to obtain good quality images, it is necessary to apply some pressure with the probe.
4. Following resting blood pressure and electrocardiogram (ECG) recordings, the patient is asked to walk on a treadmill or pedal a stationary bicycle. The treadmill starts off slowly and the speed and incline increase at set intervals. On the bicycle, the resistance is very light at the beginning but increases as the test goes on.
5. The effectiveness of a stress echocardiogram relies on the effort made by the patient. It is very important that the patient walks/pedals as long as possible.
6. Blood pressure is monitored throughout the procedure. Should a problem occur, the technician would stop the test immediately. A nearby cardiologist would be called if necessary.
7. It is very important for the patient to tell the technician if he or she experiences any symptoms, such as chest pain, dizziness, unusual shortness of breath, or extreme fatigue.
8. At the end of exercise, the patient is instructed to lie down, as quickly as possible, in the same position as when the before-exercise images were taken. The sonographer quickly acquires the necessary echo images.
9. The patient’s blood pressure and ECG are monitored for five to ten minutes after exercise.
10. A final set of echo pictures is acquired before the end of the test.
11. The ECG tracings and the echo images are reviewed by a cardiologist, and a report is sent to the patient’s doctor, who will discuss the results with them.

Special Instructions

To help ensure accurate results, patients should take the following steps in preparation for a stress echocardiogram:

• Refrain from strenuous activity for 12 hours before the test.
• Do not eat, drink, or smoke for two hours prior to the test. Unless instructed otherwise by their physicians, patients should continue to take prescribed medications. Patients who have used Viagra (sildenafil citrate) within the 24 hours prior to the test, should tell the technician. It may compromise the safety of the test.
• Wear comfortable walking shoes and clothing for the test.

 

Additional Information

An echocardiogram is not harmful in any way. However, patients might feel slight discomfort from the applied pressure of the probe.

A stress echocardiogram is not painful, but it is physically demanding. Most patients experience some degree of fatigue.

There is a very small risk of complications (heart attack, irregular heart rhythm). Everything is done to prevent such an occurrence. Medical staff and emergency equipment are immediately available to assist in the event of an emergency.