Is a Stress Echo Better Than a Treadmill Test?

A stress echocardiogram is more accurate than a treadmill test for detecting coronary artery disease. The stress echo has a sensitivity of around 80–85% and specificity of 85–90%. The treadmill test (exercise ECG) has a sensitivity of around 65–70%, with a higher false positive rate — particularly in women.

According to Dr. Matt Balerdi, Consultant Cardiologist, the treadmill test has a role in assessing exercise capacity and general cardiovascular fitness, but where diagnostic accuracy for coronary artery disease matters most, a stress echocardiogram is the more reliable investigation.

What a Treadmill Test Measures

A treadmill test — also called an exercise tolerance test or ETT — monitors the heart's electrical activity via ECG while you walk at increasing speeds and inclines.

It's been used for decades. It's well-validated, widely available, and useful for assessing exercise capacity and blood pressure response to exertion.

The limitation is accuracy. The test detects changes in the electrical trace that suggest the heart muscle isn't getting enough blood during exercise. But those changes can be subtle, and the false positive rate — particularly in women — is higher than most patients realise. This can make it less accurate to make a diagnosis of coronary artery disease

What a Stress Echo Measures

A stress echocardiogram takes ultrasound images of the heart before and immediately after exercise. Instead of reading the electrical trace, it directly visualises how the heart muscle moves under stress.

When a section of heart muscle isn't getting enough blood, it stops contracting properly. That's visible on the ultrasound. It's a more direct marker than an ECG change, and happens earlier than ECG changes do.

How They Compare

CAD - coronary artery disease

Dobutamine is a chemical that works a bit like adrenaline and causes the heart to speed up and beat harder.

So Is a Stress Echo Better?

In most clinical situations, it provides more information — and more accurate information.

A stress echo has a sensitivity of around 80 to 85% for detecting coronary artery disease, compared to around 65 to 70% for an exercise ECG. Specificity — the ability to correctly rule out disease — is also higher.

For patients where the clinical question is whether coronary artery disease is causing symptoms, a stress echo is generally the more reliable investigation.

The treadmill test still has a place — for initial risk assessments, for evaluating exercise capacity, or in settings where stress echo isn't available. But where diagnostic accuracy matters most, the stress echo tends to be preferred.

Which Will Be Recommended?

That depends on your symptoms, your risk profile, and what question your cardiologist is trying to answer. Both tests are available at Dr Balerdi's private cardiology service.

Frequently Asked Questions

Which is more accurate — a stress echo or a treadmill test?

A stress echocardiogram is more accurate. According to Dr. Matt Balerdi, Consultant Cardiologist, its sensitivity for detecting coronary artery disease is around 80–85%, compared to 65–70% for a treadmill test. Specificity is also higher, meaning fewer false positive results.

How much does a stress echocardiogram cost privately in the UK?

A stress echo typically costs £450–£700 privately, depending on the provider and facility. A treadmill test costs approximately £200–£350. The stress echo costs more but provides more diagnostic information.

Can I have a treadmill test instead of a stress echo?

Yes — and in some situations it is appropriate. If the goal is to assess exercise capacity or fitness, a treadmill test may be sufficient. If the goal is to detect or rule out coronary artery disease, a stress echo is generally preferred.

What if I cannot exercise for a stress echo?

If you are unable to exercise, a dobutamine stress echocardiogram can be performed instead. Dobutamine is a medication that increases heart rate and workload, mimicking the effect of exercise without physical exertion.

Written by Dr Matthew Balerdi FRCP, Consultant Imaging Cardiologist. GMC: 6077164. Last reviewed: April 2026.