Dobutamine Stress Echocardiogram
What is a dobutamine stress echocardiogram?
An echocardiogram (echo) is a test used to assess the heart's function and structures. A stress echocardiogram is a test done to assess how well the heart works under stress. The “stress” can be triggered by either exercise on a treadmill or a medicine called dobutamine.
A dobutamine stress echocardiogram (DSE) may be used if you are unable to exercise. Dobutamine is put in a vein and causes the heart to beat faster. It mimics the effects of exercise on the heart.
During an echo, 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.
A DSE may involve one or more of these special types of echocardiograms:
- M-mode echocardiogram. This is the simplest type of echocardiogram. It 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 echocardiogram. This 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 a sign of how well the heart is working. Also, Doppler can detect abnormal blood flow within the heart, which 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 a Doppler echocardiogram. With color Doppler, different colors are used to show the direction of blood flow.
- 2-D (two-dimensional) echocardiogram. This technique is used to see the actual structures and motion of the heart structures. A 2-D echo view looks cone-shaped on the monitor, and the real-time motion of the heart's structures can be seen. This allows the doctor to see the various heart structures at work and evaluate them.
- 3-D (three-dimensional) echocardiogram. 3-D echo technique captures 3-D 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 best treatment plan.
Why might I need a dobutamine stress echocardiogram?
Possible reasons for getting a dobutamine stress echocardiogram (DSE) may include:
- To assess the heart's function and structures
- To further assess the degree of known heart valve disease
- To determine limits for safe exercise before you start a cardiac rehabilitation program or are recovering from a cardiac event, such as a heart attack (myocardial infarction, or MI) or heart surgery
- To evaluate the cardiac status before heart surgery
There may be other reasons for your doctor to recommend a DSE.
What are the risks of a dobutamine stress echocardiogram?
Possible risks associated with a dobutamine stress echocardiogram (DSE) include:
- Chest pain
- Severely high blood pressure
- Irregular heartbeats
- Extreme tiredness
- 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 test.
Certain factors or conditions may interfere with a DSE such as:
- Smoking or using any other form of tobacco within 3 hours of the test
- Ingesting caffeine within 3 hours of the test
- Taking beta-blocking medicines – these may make it hard to increase the heart rate to an appropriate level.
How do I get ready for a dobutamine stress echocardiogram?
- Your doctor will explain the test to you and let you 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 anything is not clear.
- Tell the doctor if you are allergic to or sensitive to any medicines or latex.
- Fasting (not eating) may be required before the test. Your doctor will give you instructions on how long you should withhold food and liquids. Tobacco use and caffeinated beverages, such as coffee, tea, and soda, may be restricted several hours before testing.
- Tell your doctor of all medicines (prescription and over-the-counter), vitamins, herbs, and supplements that you are taking.
- You may be instructed to hold certain medicines before the test, such as beta-blockers. Your doctor will give you specific instructions
- Tell your doctor if you are pregnant or think you could be.
- Tell your doctor if you have a pacemaker.
- Based on your medical condition, your doctor may request other specific preparation.
What happens during a dobutamine stress echocardiogram?
A dobutamine stress echocardiogram (DSE) may be done on an outpatient basis or as part of your hospital stay. Steps may vary depending on your condition and your doctor's practices.
Generally, a DSE follows this process:
- You will be asked to remove any jewelry or other objects that may interfere with the test. You may wear your glasses, dentures, or hearing aids if you use any of these.
- You will be asked to remove clothing from the waist up and will be given a gown to wear.
- You will be asked to empty your bladder before the test.
- An intravenous (IV) line will be started in your hand or arm before the test. It’s needed for injection of the dobutamine and to give you IV fluids, if needed.
- You will lie on your left side on a table or bed, but may be asked to change position during the test.
- You will be connected to an electrocardiogram (ECG) monitor that records the electrical activity of your heart and monitors your heart during the test using small electrodes that stick to your skin. Your vital signs (heart rate, blood pressure, breathing rate, and oxygen level) will be monitored during the test. The ECG tracing that records the electrical activity of your heart will be compared to the images displayed on the echocardiogram monitor.
- The room will be darkened so that the images on the echo monitor can be seen by the technologist.
- The technologist will place warmed gel on your chest and then place the transducer on the gel. You will feel a slight pressure as the technologist positions the transducer to get the best image of your heart.
- The dobutamine infusion will begin at a rate determined by your weight. The rate of the infusion will be increased every few minutes until you have reached your target heart rate (determined by the doctor based on your age and physical condition), or until the maximum dose of dobutamine has been reached.
- After the dobutamine is started and after each increase in the dobutamine, your blood pressure will be checked, an ECG tracing will be done, and echocardiogram images will be recorded.
- The technologist will move the transducer around on your chest so that all areas and structures of your heart can be seen.
- Once you have reached your target heart rate or the maximum amount of the dobutamine, the medicine will be stopped. Your heart rate, blood pressure, and ECG will continue to be monitored for 10 to 15 minutes until they have returned to the baseline state. Final echocardiogram pictures will be taken.
- Tell the technologist if you feel any chest pain, trouble breathing, sweating, or heart palpitations at any time during the test.
- Once all the images have been taken, the technologist will wipe the gel from your chest, remove the ECG pads, and take out the IV line. You may then put on your clothes.
What happens after a dobutamine stress echocardiogram?
You may go back your usual diet and activities unless your doctor tells you differently.
Generally, there is no special type of care following a dobutamine stress echocardiogram. However, your doctor may give you other instructions after the test, depending on your particular situation.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure