Why is the doctor performing this test?
To determine how well the heart is pumping blood through the coronary arteries.
What is the test?
A Dobutamine Stress Echo is a non-invasive ultrasound test which is used to visualize the heart in motion. To view the heart, your doctor will place a transducer on your chest which emits harmless sound waves to your heart. These sound waves generate pictures of your heart in motion and are displayed on an ultrasound machine connected to the transducer.
Your doctor will examine the muscle movement of the heart (also called wall motion) while you are at rest. Then, your doctor will inject a medication called Dobutamine through an IV. This causes your heart to beat faster, simulating the effects exercise has on your heart. The doctor will then examine these pictures of your heart and compare them to the pictures taken while you were at rest.
If the results of your stress echo show decreased muscle movement (or wall motion) during stress than while resting, it is an indicator that there could be plaque buildup (Atherosclerosis) in your arteries. The doctor will determine if any other testing is necessary to ensure that your heart is functioning properly.
What is Dobutamine?
Dobutamine is a positive inotropic agent and mild chronotropic agent, meaning it increases the contractility of the heart with minimal changes in heart rate. When Dobutamine is administered, you may feel your heart pound for a few minutes. This is normal. However, you may also experience side effects such as chest pain/pressure, headache, dizziness, nausea, shortness of breath, shaky, warm and flushed. If you begin to notice these symptoms or other symptoms that concern you, notify the lab personnel immediately.
Most patients do not experience any side effects. Dobutamine has a short cycle of activity, so its effects do subside quickly.
What does the test show?
A Dobutamine Stress test evaluates the function of your heart under stress, in particular, it examines the left ventricle (the main pumping chamber of your heart). This test provides the following valuable information:
- Your risk of developing heart disease.
- Whether the symptoms you experience (ie., chest pain, shortness of breath, unexplained fatigue, dizziness, etc.) are caused by a blockage to your heart.
- Possible heart troubles that are not present at rest.
- As a tool to clear patients for cardiac surgery (or other procedures).
- To approximate the severity of the blockages to your heart.
- Following balloon angioplasty or bypass surgery (for those who require these procedures), a stress test may help to determine the success of the procedure and an appropriate rehabilitation program for you.
How do I prepare for the test?
- Do not eat or drink anything 4 hours prior to the test. This helps prevent nausea and vomiting – possible side-effects which may accompany the infusion of Dobutamine. Diabetics and those who need to eat/drink with medication(s) must get special instructions from their doctor.
- Do not smoke 4 hours prior to the test. Smoking can produce inaccurate test results.
- Wear a two-piece outfit as women will wear a hospital gown and men are asked to remove their shirt.
- Do not wear oils or lotions. Small sticky patches called electrodes must stick on your chest.
- Do not take the following heart medications on the day of your test unless your physician tells you otherwise or if the medication is needed to treat chest discomfort:
- Beta Blockers e.g., Tenormin, Lopressor, Propanolol)
- Isosorbide dinitrate (e.g., Isordil, Sorbitrate)
- Isosorbide mononitrate (e.g., Ismo)
- Nitroglycerin (e.g., Deponit, Nitrostat)
- If you have questions about medications you take, talk to your physician.
Please Note: Do not discontinue any medication without first talking with your physician
Where is the test performed?
In various outpatient centers, such as your cardiologist’s office.
How long does this test take?
Approximately 30 – 45 minutes:
- Prep: 10 – 15 minutes
- Testing: 15 minutes
- Recovery: 10 – 15 minutes