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Transoesophageal echocardiogram (TOE) - private in London.

The high-resolution echo done from behind the heart, under sedation, when a standard scan cannot answer the question.

A private London cardiac imaging suite prepared for a transoesophageal echocardiogram

What it is

An echo from behind the heart, not through the chest.

The oesophagus sits directly behind the left atrium, giving the ultrasound probe an uninterrupted view of structures that lung and rib block from the front.

A transoesophageal echocardiogram - TOE in the UK, TEE in the US - uses a slim ultrasound probe on the end of a flexible tube, passed gently down the oesophagus after throat spray and mild intravenous sedation. Because the probe sits within a few millimetres of the back of the heart, resolution is markedly higher than a standard chest wall (transthoracic) echo. Small vegetations, tiny leaflet defects, prosthetic valve mechanics and left atrial appendage clot all become visible in a way they simply are not from the front.

A consultant cardiologist performs the study, usually with an anaesthetic assistant to give and monitor the sedation. Scanning itself takes 15 to 30 minutes. Total time in the department, including consent, cannula, sedation and recovery, is typically 60 to 90 minutes. You go home the same day, escorted by a friend or family member, and you do not drive for the rest of the day.

In short

  • Where: from inside the oesophagus, behind the heart.
  • Sedation: throat spray + IV midazolam/fentanyl.
  • Scan time: 15-30 minutes.
  • In and out: 60-90 minutes.
  • Cost in London: £900-£1,600 all in.

Who it is for

When a standard echo is not enough.

Most cardiac questions are answered with a transthoracic echo. A handful genuinely need a TOE, and getting the right test first saves weeks.

  • Suspected infective endocarditis

    Positive blood cultures, new murmur, embolic phenomena, prosthetic valve or intracardiac device in situ.

  • Source of embolus after stroke or TIA

    Looking for LA appendage clot, PFO, ASD, aortic arch atheroma or endocarditis in cryptogenic stroke.

  • Pre-cardioversion clot screen

    Excluding LA appendage thrombus before elective DC cardioversion or AF ablation when anticoagulation is uncertain.

  • Mitral valve disease detail

    Prolapse mechanism, flail segments and regurgitant jet before repair or MitraClip.

  • Prosthetic valve assessment

    Suspected obstruction, paravalvular leak, thrombus or pannus around a mechanical or bioprosthetic valve.

  • Aortic root and dissection

    Acute chest pain with suspected type A dissection, or follow-up of a known root aneurysm.

  • TAVI and MitraClip planning

    Pre-procedural sizing and intra-procedural guidance in the cath lab or hybrid theatre.

  • Congenital heart disease

    Detailed septal anatomy, complex adult congenital cases and pre-closure PFO/ASD work-up.

  • Uninterpretable transthoracic study

    Very difficult acoustic windows - obesity, chronic lung disease, chest wall deformity or ventilated patients.

Preparation

The five things to sort before you arrive.

The clinic sends written pre-procedure instructions. These are the points patients most often ask about.

  • Fast for six hours

    Nothing to eat for six hours before the procedure. Small sips of water up to two hours before are usually allowed.

  • Arrange a companion

    Sedation means you cannot drive, cycle or operate machinery for 24 hours. A friend or family member should collect you.

  • Anticoagulation review

    Warfarin, DOACs or antiplatelets may need adjusting, or may need to stay on board if the study is looking for clot before cardioversion. Your cardiologist advises case by case.

  • Throat spray and IV cannula

    A local anaesthetic spray numbs the back of the throat. A cannula in the back of the hand delivers mild sedation - usually midazolam with a small dose of fentanyl.

  • Dental check

    Loose teeth, crowns and dentures are noted. Dentures come out for the study. A bite guard protects your teeth and the probe.

The procedure

Step by step, on the day.

You will be looked after by a consultant cardiologist, a specialist echo physiologist and a nurse throughout.

  1. 01

    Consent and checks

    A short conversation about the study, risks, and what the cardiologist is looking for. Dentures out, a bite guard prepared.

  2. 02

    Throat spray

    Lidocaine spray to the back of the throat. Tastes bitter for a moment, then the pharynx goes numb over a minute or two.

  3. 03

    IV sedation

    A cannula in the back of the hand delivers midazolam and a small dose of fentanyl. You feel calm and drowsy within a minute.

  4. 04

    Probe passed

    You lie on your left side. The probe is guided through the mouth and down 30-40 cm as you swallow once.

  5. 05

    Scanning

    15-30 minutes of quiet imaging. You breathe normally. Oxygen, ECG, blood pressure and oxygen saturation are monitored throughout.

  6. 06

    Recovery

    The probe is removed and you rest for 30-60 minutes while the sedation wears off. A drink and a snack once your swallow is back to normal.

Diagnostic edge

What TOE sees that a standard echo cannot.

The structures where an oesophageal window materially changes the answer.

  • Left atrial appendage

    The most reliable way to exclude clot in the LAA before cardioversion or AF ablation. Transthoracic echo cannot see this reliably.

  • Small vegetations

    Tiny valve vegetations in suspected infective endocarditis, well below the resolution of a transthoracic study.

  • Mitral valve leaflets

    Leaflet anatomy, prolapse, flail segments and regurgitant jet mechanism for repair planning.

  • Prosthetic valves

    Mechanical and bioprosthetic valves are much better assessed from behind, without lung and rib shadowing.

  • PFO and ASD

    Patent foramen ovale and atrial septal defects, often with a bubble study, for stroke work-up or closure planning.

  • Aortic root and arch

    Aortic dissection, intramural haematoma and root pathology in acute chest pain.

Cost in London

£900 to £1,600, all in.

What is included Indicative range
TOE, sedation, consultant cardiologist, day-case recovery£900 - £1,600
Combined TOE and DC cardioversion (day case)£2,200 - £3,500
Consultant cardiology consultation (if needed first)£250 - £400

Variables: private cardiologist fees, whether the sedation is given by an anaesthetic assistant or by the cardiologist, and whether the hospital charges day-case theatre time or a diagnostic slot.

Where it is done

Tertiary cardiac centres with day-case pathways, on-site anaesthetic cover and sub-speciality cardiologists.

  • Royal Brompton (Private Care)

    Chelsea

  • Barts Heart Centre Private

    City of London

  • HCA The Wellington Hospital

    St John's Wood

  • HCA London Bridge Hospital

    Southwark

  • Cromwell Hospital (Bupa)

    Kensington

  • OneWelbeck Heart Health

    Marylebone

Risks

A safe test, honestly described.

Serious complications are rare. The full consent conversation happens with the cardiologist on the day.

  • Sore throat

    Common for 24-48 hours. Warm drinks and simple pain relief settle it.

  • Dental damage

    Rare. The bite guard protects both your teeth and the probe. Loose crowns are flagged in advance.

  • Oesophageal injury

    Rare - roughly fewer than 1 in 5,000. Higher in known strictures or varices, which is why we screen first.

  • Sedation effects

    Drowsiness, mild nausea or a short dip in blood pressure. Monitored throughout and reversed if needed.

  • Bleeding

    Minor throat bleeding is uncommon and settles on its own.

Related pages

Around this test.

Where a TOE sits alongside other cardiac imaging and the conditions and treatments it most often supports.

Frequently asked

About sedation, insurance and results.

The six questions we hear most from patients before a private TOE.

  • Do I have to be sedated for a TOE?

    Almost always yes. A throat spray alone is possible but rarely tolerated - the gag reflex makes it very difficult. Standard practice in London is a throat spray plus intravenous midazolam and a small dose of fentanyl. You are drowsy but breathing on your own and can respond to simple instructions. Full general anaesthesia is only used when a TOE is combined with a procedure such as cardioversion, TAVI or MitraClip.

  • Can I drive home afterwards?

    No. Sedation stays in your system for the rest of the day. You cannot drive, cycle, operate machinery, sign legally binding documents or drink alcohol for 24 hours. A friend or family member should collect you from the clinic, and ideally stay with you overnight.

  • What about my gag reflex?

    The throat spray numbs the pharynx and the sedation blunts the reflex. Most patients remember very little of the probe passing. You are asked to swallow once as the probe is guided down, and after that it sits quietly in the oesophagus while imaging runs.

  • I wear dentures - is that a problem?

    No. Dentures are removed before the study for safety and to allow the bite guard to sit properly. You get them back as soon as the probe is out. Tell the team about any crowns, bridges or loose teeth so they can be protected.

  • Will my insurance cover a private TOE?

    Most comprehensive UK policies cover TOE when medically indicated - suspected endocarditis, pre-cardioversion clot screen, prosthetic valve assessment, source of embolus after stroke, or MitraClip and TAVI planning. Pre-authorisation is straightforward with a consultant referral.

  • When do I get the results?

    The cardiologist usually gives you a verbal summary once the sedation has worn off, before you go home. A full written report with images follows within 24 to 72 hours and is sent to you and to your GP or referring specialist.