Stress Echocardiography

A stress echocardiogram is a non-invasive test available in Singapore. It uses ultrasound (high-frequency sound waves) to take moving images of your heart while it is under physical or medically induced stress.

At rest, a narrowed artery may supply just enough blood to the heart muscle to keep things normal. Under exertion, that supply may fall short of what the heart needs. The test captures images before and after stress, then compares them. If a section of the heart wall moves abnormally during stress but not at rest, this suggests reduced blood flow to that area.

It is a variant of the standard resting echocardiogram. If you have already had a transthoracic echocardiogram (TTE), a stress echo adds the exertion element on top of that baseline picture.

Your cardiologist may suggest a stress echo test if you have been experiencing chest tightness during exertion, breathlessness when climbing stairs, or an unexplained abnormal result on a treadmill electrocardiogram (ECG) test. It is also used to monitor patients who have had coronary stenting or who have known valve disease.

Specifically, the test helps to:

• Confirm whether your symptoms are caused by coronary artery disease (a narrowing of the arteries that supply the heart)
• Assess how well your heart and valves function under load
• Measure how well your heart tolerates physical activity
• Evaluate whether your current cardiac treatment plan is working

Not sure if your symptoms point to a heart problem? A stress echo test can give you a clear answer. Contact us to find out if it is the right test for you.

Will a stress echo show blockages?

A stress echo does not directly visualise a blockage inside an artery. What it detects is the effect of reduced blood flow: abnormal wall motion in the heart muscle during stress. If the test is abnormal, further investigations, such as a CT coronary angiography (CTCA) or coronary angiography, may be arranged to look at the arteries directly.

Different tests answer different questions. The table below shows where a stress echo test sits relative to other common investigations.

A stress echocardiogram is more accurate than an exercise treadmill ECG alone at detecting reduced blood flow to the heart muscle. This is because it combines electrical data with direct imaging of how the heart wall actually moves, which is information a treadmill ECG does not provide.

There are two ways to stress the heart during this test.

If you cannot walk on a treadmill, the dobutamine option achieves the same diagnostic result using medication to raise your heart rate instead.

Exercise Stress Echocardiogram

1. Resting echocardiogram
   • You will be asked to undress from the waist up and wear a gown.
   • Small adhesive electrodes (sticky patches) are placed on your chest and connected to an ECG machine, which monitors your heart rhythm throughout.
   • Chest hair may need to be shaved for the patches to stay in place.
   • You then lie on your left side while the sonographer applies gel to your chest and uses an ultrasound probe to take images of your heart.
   • The probe is held firmly against your chest; this may feel like mild pressure but should not be painful.
2. Treadmill exercise
   • You will walk on a treadmill, which becomes steeper and faster every three minutes.
   • Our team at Capital Heart Centre will monitor your blood pressure and heart rate continuously.
     The treadmill stops when you reach your target heart rate, or earlier if you develop symptoms that prevent you from continuing.
3. Post-exercise echocardiogram
   • Immediately after the treadmill stops, you lie back on your left side.
   • The sonographer takes a second set of images while your heart rate is still elevated, which are then compared against the resting images.

The whole process takes about 60 to 90 minutes, with the actual exercise lasting around six to 12 minutes.

Dobutamine Stress Echocardiography

The resting echocardiogram stage follows the same process explained earlier. In addition, a small cannula (a fine needle attached to a tube) is inserted into a vein in your hand.

1. Dobutamine infusion.
   • Once the resting images are taken, dobutamine is delivered through the cannula.
   • The medication raises your heart rate, causing your heart to beat faster and harder.
   • You may feel mildly breathless or notice your heart racing. These are expected effects and resolve within minutes of the infusion stopping.
   • If your heart rate does not reach the target with dobutamine alone, a small amount of atropine may be added.
2. Dobutamine echocardiogram. The sonographer takes images during and after the infusion for comparison with the resting set.

The infusion itself lasts around 15 minutes. Your heart rate returns to normal within five to 10 minutes of it stopping.

Serious complications from this test are extremely rare. Our team at Capital Heart Centre will monitor you continuously throughout, and the facility is equipped to manage any adverse event should one occur.

There is no radiation exposure. The echocardiogram uses ultrasound waves only.

You may feel mild discomfort from the probe being held firmly against your chest. This is necessary to acquire clear images.

In the unlikely event of a serious complication, your doctor is present and treatment is available on site.

Serious complications are rare, and our team monitors you throughout. If you are ready to book, or just want to ask a question first, contact us.

After an exercise stress echocardiogram, you will rest for at least 30 minutes before leaving. After that, you can return to your usual activities.

After a dobutamine stress echocardiogram, you may be observed for longer or monitored as an inpatient. Arrange for someone to drive you home; do not drive yourself after a dobutamine test.

Your cardiologist will review the results and discuss them with you at your next appointment. You will be contacted sooner if the findings require prompt attention.

If the result is abnormal, your cardiologist may recommend further investigations, such as a CT coronary angiography, nuclear myocardial perfusion imaging, or a coronary angiography, to look more closely at the coronary arteries.

Capital Heart Centre offers both exercise and dobutamine stress echocardiography at Mount Elizabeth Novena Specialist Centre, 38 Irrawaddy Road, Singapore 329563.

The test is performed and reported by Dr Joshua Loh, Senior Consultant Interventional Cardiologist and Medical Director of Capital Heart Centre. Dr Loh holds fellowships from the Royal College of Physicians (Edinburgh), the American College of Cardiology, and the Society for Cardiovascular Angiography and Interventions, and has more than 20 years of experience in cardiology with a focus on complex coronary and interventional procedures.

Will a stress echo show blockages?

A stress echo does not directly visualise a blockage inside an artery. What it detects is the effect of reduced blood flow: abnormal wall motion in the heart muscle during stress. If the result is abnormal, a CT coronary angiography or coronary angiography may follow to look at the arteries directly.

How long does a stress echo test take?

The full appointment is 60 to 90 minutes. The exercise itself lasts around six to 12 minutes; the dobutamine infusion around 15 minutes. You will also need to rest for at least 30 minutes before leaving after an exercise stress echo.

What is a stress echocardiography test?

It is an ultrasound test that images your heart while it is under physical or medication-induced stress, to check for reduced blood flow or abnormal heart function that only appears during exertion. See the full explanation above.

How do I prepare for a stress echo test?

Fast for at least two hours before the test. Avoid all caffeine for 24 hours beforehand. Do not smoke or drink alcohol on the day. Check with your cardiologist whether to pause any heart rate medications. Full details are in the preparation section above.

Does a stress echocardiogram hurt?

No. You may feel mild pressure from the ultrasound probe on your chest, and some breathlessness during the exercise or dobutamine phase. These are expected and resolve once the test ends.

Can I drive home afterwards?

After an exercise stress echocardiogram, yes. After a dobutamine stress echocardiogram, you should arrange a driver. Do not drive yourself after the dobutamine test.

What if I cannot walk on a treadmill?

The dobutamine protocol is available for exactly this situation. Medication raises your heart rate instead, producing the same diagnostic effect without exercise.

Is a stress echocardiogram more accurate than a treadmill ECG?

For detecting reduced blood flow to the heart muscle, yes. A treadmill electrocardiogram (ECG) records the heart’s electrical activity but does not show how the heart wall is actually moving. A stress echo test adds that imaging layer, which makes it more sensitive to wall motion abnormalities. See the comparison table above for a fuller breakdown.

Do I need a referral?

You are welcome to contact Capital Heart Centre directly to arrange a consultation. Your GP or specialist may also refer you. Contact us at (65) 8071 5822 or via the enquiry form to discuss your situation.

To arrange a stress echocardiogram or discuss whether the test is right for you, contact our team directly.

Call or WhatsApp us at (65) 8071 5822. We aim to respond to all enquiries within one business day. Please let us know your preferred appointment time and whether you are a new or returning patient.