Advice after your nerve block for surgery
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What is a Transoesophageal Echocardiogram (TOE)?
An echocardiogram (echo) is an ultrasound scan that uses sound waves (ultrasound) to produce real time images of your heart. There are several different types of echocardiograms. You may have already had a routine transthoracic echocardiogram where a handheld probe is moved across your chest and the images are displayed on the screen of the echo machine.
Sometimes more detailed and closer imaging of the heart is required. To achieve this your doctor may recommend a transoesophageal echocardiogram (TOE), where images are obtained using a flexible ultrasound probe that is passed into your oesophagus (gullet). The oesophagus lies behind the heart and there is no interference from the ribs or lungs.
What are the benefits of a TOE?
A TOE is used to assess the structure and function of the heart, including structures that are less visible on routine transthoracic echocardiogram. It can help the doctor in finding the reasons for your cardiac symptoms. It can be used to check if the heart valves are leaking or narrowed or an infection is suspected on the heart valves.
A TOE can check for clots in the heart. It is also useful to help guide further treatment and if surgical treatment is required it can provide the surgeon with important information.
Preparing for the procedure
The TOE procedure is usually performed as a day case in hospital by a Cardiology Consultant. You will have been asked not to eat or drink anything for 6 hours before your appointment time. If you need to take prescribed medicines, please swallow with small sips of water only. This includes blood thinning medication such as warfarin but do let the nurses and doctor know if you are taking these.
Please note that the appointment time is not the actual time of your procedure as you’ll need to be prepared for the procedure first. Please bring a list of all your medication with you in case the Consultant needs to review it after the test
Before the procedure
When you arrive at the Cardiac Catheter Lab please report to reception where the reception staff will check you in and ask you to take a seat in the waiting area. When the nurse is ready for you, they will call you through and prepare you for the procedure. You will be asked to remove the clothes from your upper body and change into a hospital gown with the opening at the front.
You then lie on a bed and your blood pressure, pulse and temperature will be taken. A cannula is also inserted into your arm. You will be asked the length of time you have been NBM, any loose teeth, dentures or dentures plates, known allergies and recent illnesses.
The Cardiology Consultant will explain the investigation again, including the risks and benefits, and will ask for your consent. They will also discuss your preference regarding the use of sedation. If you have any questions, please do ask. Although this is covered in the checklist, please let us know if you are allergic to anything, have diabetes, take blood thinners, have any problems swallowing or have had gastric or oesophageal surgery.
You will be asked to remove any dentures, or denture plates, and glasses. Three ECG leads are attached to your chest to monitor your heart rhythm during the scan. The Cardiologist will spray a local anaesthetic to the back of your throat to numb it. This will help the ultrasound probe pass more easily down your throat and reduce your gagging reflex. You will then lie on your left side and the lights are turned down.
During the procedure
A plastic mouth guard is placed between your teeth to help protect the probe and your teeth. If you would like sedation it will be given via your cannula. This will help to make you relaxed and sleepy but not completely unconscious.
The ultrasound probe will be placed into your mouth and you will be asked to swallow it so that it passes down the back of your throat and into your oesophagus. The TOE procedure does not interfere with your breathing in any way but sedatives can sometimes affect your breathing. We will therefore give you extra oxygen, via soft tubes inside the nostrils, and monitor the oxygen levels in your blood via a finger probe.
The procedure will last approximately 15 minutes while the Consultant obtains images that are displayed on the screen. Any saliva produced will be removed using a suction tube similar to the one used at a dentist.
After the procedure
Your blood pressure will be taken and you will be monitored for a short period. You may feel a little drowsy, if you have had sedation, but this usually wears off within 30 minutes. Once you feel lucid and the Consultant is happy, your cannula will be removed and you can get dressed. The Consultant will send the results of your TOE to the doctor who requested the test but may also be able to talk you through the results at the time.
Discharge Home
If you have not had sedation you will be able to go home shortly after the procedure. If you have had sedation you will usually go home within half an hour. Sedation temporarily affects your co-ordination and clarity in thinking so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours.
Therefore, if you have had sedation you will need to arrange for someone to collect you, ideally from the Cardiac Catheter Lab, and stay with you for the rest of the day.
Whether or not you had sedation you will have had local anaesthetic spray to numb your throat. This can temporarily affect your swallowing so it is important not to eat or drink anything for 1 hour after the procedure. You will be given written instructions with all the advice following a TOE and the nurse will go through this with you.
Alternative Procedures
- Transthoracic echocardiogram (TTE). Although as discussed this produces less detailed images of certain areas of the heart.
- Cardiac Magnetic Resonance Imaging (MRI) scan is a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of your heart.
- Cardiac Computed Tomography (CT) Scan uses x-rays to take high quality three-dimensional cross-sectional images of the heart.
Risks
- Sore Throat
- Laryngospasm (spasm of the vocal cords) <1%
- Aspiration of saliva into the lung <1%
- Oesophageal perforation 1:10,000
- If having sedation there is also a risk of transient low blood pressure, low oxygen levels, or heart rhythm disturbance.
If you have any questions before your test, please ring the Cardiac Bookings Office on 03006 133337.
The procedure takes place in the Cardiac Catheter Lab Department.
Please note that this is about 400 metres from the Main Entrance so please allow extra time to get here and for parking.
If you think you will not be able to walk this far then please use a wheelchair (there are some available in the Main Entrance) or ask at Reception for a Porter to take you.
Contact us
If you have any queries relating to this information, please contact the Cardiology service.
About this information
Service:
Cardiology
Reference:
C/024
Approval date:
1 August 2025
Review date:
1 August 2028
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Important note
This page provides general information only. It is developed by clinical staff and is reviewed regularly every 3 years for accuracy. For personal advice about your health, or if you have any concerns, please speak to your doctor.