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Echocardiogram (echo)

This test can also be called a transthoracic echocardiogram, but is usually referred to simply as an echocardiogram or echo for short.

What is an echocardiogram?

An echocardiogram, also known as an echo, is a test that uses sound waves to build up a moving picture of the heart. It is similar to the ultrasound scan used in pregnancy and is extremely safe. 

The ultrasound waves reflect against structures in the heart to measure the size and function of your heart and to check how well your heart is working. 

An echo can also show the direction and velocity of blood flowing through your heart and across your heart valves.

How is an echocardiogram performed?

A doctor or cardiac physiologist will perform the echo. We will ask you to remove your clothes from the waist up and to lie on an echocardiogram bed on your back. We may ask you to roll over onto your left-hand side during the test.


Three small sticky patches, called electrodes, will be attached to your chest and connected to the echo machine. We will place a small hand-held transducer (echo recorder) on your chest. This will have a small amount of lubricating jelly on it. 

Images of your heart will then be taken from different positions on the chest. The recorder sends high-frequency sound waves to the heart and records the echoes of sound waves reflected back from your heart. 

The echocardiography machine receives these echoes as electrical impulses and converts them into moving pictures of the heart.


Once the images can be seen clearly, in some situations the doctor or technician may inject contrast (dye) during the echo and ask you to perform some special breathing exercises. 

This will allow us to obtain additional information to help us diagnose.

Contrast can improve the quality of the image and allow us to see some structures within the heart more clearly. It can also be used to give us more information on blood flow within the heart. 

Why do I need an echocardiogram?

An echo gives detailed images of your heart. It allows us to accurately assess the size of your heart, its chambers and how your heart valves are functioning. 

We can also examine the direction and velocity of blood flowing through your heart.


An echo allows doctors to diagnose, assess and regularly check:

  • heart murmurs

  • abnormal heart valves

  • atrial fibrillation

  • pump function in patients with damaged heart muscle (after heart attacks)

  • pump function of the heart for people with heart failure

  • infection on heart valves (infective endocarditis)

  • fluid collections around the heart (pericardial effusion)

  • the source of a blood clot after transient ischemic attack/stroke

  • congenital heart disease

  • pulmonary hypertension.

How safe is an echocardiogram?

An echocardiogram is extremely safe. There are no known risks from the clinical use of ultrasound during this type of testing. 

An echocardiogram is non-invasive, there are no known side-effects of ultrasound and no radiation is used.

How long does an echocardiogram take?

A short examination in an uncomplicated case may be performed in 15-20 minutes. The additional use of Doppler (a special part of the ultrasound examination that looks at blood direction and velocity) may add an extra 10-20 minutes. 

However, it may take up to an hour when there are multiple heart problems and the echocardiogram is more complicated.

If contrast is being used, it can take between 30 minutes and one hour.

When can I expect to receive the results?

A doctor or cardiac physiologist will report on your echocardiogram immediately after the test. The results will then be sent to your cardiologist or doctor who will be able to discuss the results with you.

Echo locations

Royal Brompton Hospital

Level 3, Chelsea wing

Royal Brompton Hospital


Contact details

Monday to Friday

9am to 5pm

Telephone: +44 (0)20 7351 8209

Fax: +44 (0)20 7351 8604

Harefield Hospital

Echocardiography clinic room

Outpatients department

Harefield Hospital


Contact details

Monday to Friday

9am to 5pm

Telephone: +44 (0)1895 823737 ext: 5586


Royal Brompton

Sydney Street,
London SW3 6NP
Tel: +44 (0)20 7352 8121