Transoesophageal echocardiogram (TOE)

Mayo Clinic Healthcare specialists in London use a transoesophageal echocardiogram (TOE) to produce more-detailed images than a traditional echocardiogram or when a standard echocardiogram fails to produce a clear picture.

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What is the purpose of a transoesophageal echocardiogram?

A transoesophageal echocardiogram shows detailed images of your heart tissue, in real time, through a small ultrasound “camera” that is placed very near your heart through your throat and into your oesophagus.

You may need a transoesophageal echocardiogram if you have abnormal function of a heart valve or your transthoracic echocardiogram identified an abnormality that may require further characterisation. A transoesophageal echocardiogram can help diagnose:

  • Heart valve problems and help to plan their management
  • Endocarditis (an infection of the heart tissue)
  • A hole between different chambers of the heart
  • An abnormal mass in the heart
  • A clot in the heart
  • A structural abnormality of the heart

How do I prepare for a transoesophageal echocardiogram?

A transoesophageal echocardiogram requires a sedative, so before you arrive at the clinic you will need to arrange for someone to accompany you home as your judgement after the scan may be impaired. The sedative will help you relax, though you will still be awake during the procedure.

Eight hours before you arrive at the clinic, you will need to stop eating solid foods, drinking alcohol and using tobacco. Two hours later (six hours before your procedure), you’ll need to stop drinking nonclear liquids such as milk and orange juice. Two hours before your procedure, you’ll stop drinking anything.

If you are on any medications, you may generally continue them unless you are told otherwise by your health care team. Rest assured, your team will work with you to ensure your medication needs are met so you can safely receive a TOE. It is not recommended that you take vitamins or supplements the morning of the procedure.

How long does a transoesophageal echocardiogram take?

Transoesophageal echocardiograms usually take an hour or less. However, you may be kept for observation for a few hours after the test. Your consultant cardiologist will normally discuss the results of your scan before you leave the clinic.

How is transoesophageal echocardiogram done?

During the procedure, a consultant cardiologist, a cardiac physiologist and a nurse will be in the room with you. You will be given enough time to understand what the procedure involves and the consultant performing your TOE will answer your questions before the procedure.

A technician will place a blood pressure cuff on your arm and an oximeter on your finger so we can measure your blood pressure, heart rate and oxygen levels throughout the TOE. A specialist will also place a fine tube, called a cannula, into a vein in your arm to deliver medications used for sedation.

Before the procedure begins, we will numb your mouth and throat with a local anesthetic to help reduce the feeling of the scope in your throat. The sedative delivered through the cannula will help you feel relaxed. Most people are asleep or rest comfortably during the TOE.

You will lie on your side with a pillow behind your back for support. You will be given a protective mouthpiece to keep you from biting the scope. The consultant cardiologist then guides the scope, a flexible tube about the width of your little finger, into your throat and asks you to swallow. You will be able to breathe normally, though you may feel a mild pressure in your throat or chest when the scope is in place.

If necessary, you may be given a microbubble contrast agent through the cannula to make the echo images clearer. A microbubble is a very small bubble of gas that dissolves on its own.

The total length of procedure, from the time you arrive until the time you are discharged, is typically between 1 to 2 hours.

How does a transoesophageal echocardiogram work?

The scope that your doctor guides into your oesophagus contains a transducer at the end. The transducer emits and collects sound wave echoes. A computer then converts that information into detailed moving images of your heart and blood vessels. Your doctor can view the images on a monitor in real time and adjust the scope to produce detailed images of your inner heart structures. We also use doppler and color techniques to check blood flow problems caused by leaking or narrowed valves.

What can I expect after a transoesophageal echocardiogram?

We recommend not eating or drinking until the numbness in your throat is gone. It usually takes about an hour, though you should avoid hot food and hot beverages for a few hours.

If you have a minor sore throat after the procedure, you can use throat lozenges and a nonaspirin pain reliever containing paracetamol.

It is important that you follow the guidelines about sedation after your TOE. Some people feel fine after sedation, though their judgement remains impaired. For the rest of the day after being sedated, you should not:

  • Drive or operate motorised vehicles or equipment
  • Travel alone
  • Return to work or school
  • Take on responsibility for children or anyone who depends on your care
  • Use exercise equipment or take part in rough play or sports
  • Drink alcoholic beverages

Sedation medication may also increase your risk of falling. So use caution and ask for help when you walk or move around.

Are there any risks of complications related to transoesophageal echocardiogram?

TOE is considered a relatively safe medical procedure. Serious complications with endoscopic procedures such as the TOE are very rare. Possible complications include a sore throat, bruising around the cannula insertion place, damage to your teeth or dental work (crowns), and very rarely damage to the oesophagus from the endoscope. Before your procedure, we will discuss your allergies and past reactions to medications to make the risk as low as possible.

If you have questions about complications, please ask your Mayo Clinic Healthcare team in London.