Dobutamine Stress Echocardiogram

Stress Echocardiogram is a diagnostic procedure combining:

• Echocardiography, which uses high frequency sound waves (ultrasound) to assess motion of heart muscles; and
• Stress test, which assesses the capacity and reserve of heart muscle function under stressful situations.

The information obtained will help the doctor to indirectly assess the status of blood supply to the heart muscle. It also provides indirect information on the viability and the function of the heart muscle.

This information is important and vital to the doctor in planning further appropriate measures and treatment for you.

There are two ways we can stress your heart: one is via the treadmill test (Exercise Stress Echocardiogram). Whereas, for this test, we will be using medication (Dobutamine) to stress the heart, simulating an exercise environment (Pharmacological Stress Echocardiogram).

Is the test safe?

The test is usually performed on patients suspected of having or already have had coronary artery disease – insufficient blood supply to the heart muscle.

Possible adverse side effects for dobutamine stress echocardiography include:

• Life-threatening heart rhythm (<0.2%)
• Non-sustained ventricular tachycardia / supraventricular tachycardia (3-4%)
• Acute myocardial infarction (0.02%)
• Stroke (<0.01%)
• Death (<0.01%)

Other side effects related to the medication may include:

• Headache / flushing
• Nausea / vomiting
• Symptomatic hypotension or hypertension
• Blurred vision / dry mouth
• Transient urinary retention, requiring urinary catheterisation (1%) if atropine is administered

As atropine may be given to increase the heart rate response during the test, patients with prostate problems or glaucoma (a condition with high pressure in the eyeball) should avoid atropine. Please inform the nurse or doctor if you have these conditions before the test.

As the test involves echocardiographic imaging using ultrasound waves, there is no risk of radiation exposure.

If you are not keen for this procedure, you will need to discuss with your doctor in your next clinic visit. Other form of stress tests may involve a radionuclide myocardial perfusion scan or a magnetic resonance stress imaging.

Can I undergo the test if I am not feeling well?

If you are feeling unwell because of fever, running nose or acute illness, you should not proceed with the procedure. Please call the NHCS Call Centre at +65 6704 2000 to reschedule the test.

Preparations before test

• Take a light meal before the test.
• Check with your doctor whether you need to stop any medication (3 days) before the test.
• Informed consent prior to the test is required. For patients below 21 years old, please be accompanied by a parent for consent taking.

How is the test done?

This form of test does not require you to perform the walking exercise on the treadmill machine. Instead, you will be given a medication called dobutamine through an infusion into the vein. The infusion rate will be increased gradually until:

• A target heart rate is achieved; or
• Symptoms such as breathlessness or chest pain occur; or
• The doctor stops the test.

During the test, you may experience a sensation of fast or pounding heartbeats. This is an expected response and you should not be unduly worried. You need to inform your doctor if you develop chest pain, breathlessness or other uncomfortable sensation. The medical technologist will perform an echocardiogram on you at various stages, namely, at the baseline, different stages of infusion of medication and during recovery period. The images obtained at various stages will be analysed side-by-side on the monitor.

The procedure will take around 1.5 to 2 hours and this does not include the waiting time.

What can I expect after the procedure?

You will be monitored for some time after the procedure if you do not feel well. If the symptoms persist, you may be admitted for observation. If the test turns out to be very abnormal, you may also be admitted for further management after discussion with your doctor.