Stress echocardiography, also called an echocardiography stress test or stress echo, is a procedure used to determine how well your heart and blood vessels are working.You will be asked to exercise on a treadmill or stationary bike while doctors monitor your blood pressure and heart rhythm. When your heart rate reaches peak levels, the doctor will take ultrasound images of your heart to determine whether your heart muscles are receiving enough blood and oxygen while you exercise.Your doctor may order a stress echocardiography test if you have chest pain and he or she suspects it is due to coronary artery disease or a myocardial infarction (heart attack). This test is also used for patients in cardiac rehabilitation to determine how much exercise their bodies can tolerate safely. The test can also determine how well treatments such as bypass grafting, angioplasty, or anti-anginal or antiarrhythmic medications are working.
How Can I Prepare for the Test?
This test is usually done in an echocardiography laboratory (echo lab), but can also be performed in a doctor’s office or other medical setting. It normally takes between 45 and 60 minutes.
Before you take the test:
- Make sure not to eat or drink anything for three to four hours before the test.
- If you are a smoker, do not smoke on the day of the test because nicotine can interfere with your heart rate.
- Do not drink coffee or take any medications that contain caffeine without consulting your doctor.
- If you take medications, ask your doctor whether you should take them on the day of the test. Certain heart medications (such as beta-blockers, isosorbidedinitrate, isosorbidemononitrate, and nitroglycerin) should not be taken before the test. Let your doctor know if you take medication to control diabetes as well.
- Wear comfortable, loose-fitting clothes. Since you will be required to exercise, make sure to wear good walking or running shoes.
What Happens During the Test?
Your doctor will need to see how your heart functions while you are at rest to get an accurate idea of how it is working. The doctor will begin by placing 10 electrodes (small, stickypatches) on your chest that are connected to an electrocardiograph (ECG). The ECG will measure your heart’s electrical activity, especially the rate and regularity of your heartbeats. You will likely have your blood pressure taken throughout the test as well.
Next, you will lie on your side and the doctor will do a resting echocardiogram, or ultrasound, of your heart. He or she will apply a special gel to your skin and then use a device called atransducer, which emits sound waves to create images of your heart’s movement and internal structures.
After the resting echocardiogram, you will exercise on a treadmill or stationary bicycle. Depending on your physical condition, the clinician may ask you to increase the intensity of your exercise. How long you will need to exercise varies from person to person, but usually between six and 10 minutes.
You will likely be asked to exercise until you feel tired to raise your heart rate as much as possible. Let the clinician know right away if you feel dizzy or weak, or if you experience chest pain or pain on your left side.
As soon as the clinician tells you to stop exercising, he or she will perform another ultrasound. This is to take more images of your heart working under stress. You will then have a cool-down period when you can walk around slowly so that your heart rate can return to normal. The clinician will monitor your ECG, heart rate, and blood pressure until the levels return to normal.
This test is safe and non-invasive. Complications are rare, but can include:
- an abnormal heart rhythm
- dizziness or fainting
- heart attack
What Do the Test Results Mean?
The echocardiography stress test is very reliable. Your doctor or cardiologist will explain your test results to you. If the results are normal, your heart is working properly and your blood vessels are probably not blocked due to coronary artery disease.
Abnormal test results may mean that your heart is not pumping blood effectively because there is a blockage in your blood vessels, or that your heart has been damaged by a heart attack.
Diagnosing coronary artery disease and assessing your risk for heart attacks early on can help prevent future complications. This test can also help determine if your current cardiac rehabilitation plan is working for you.