Ilyas K. Colombowala, MD, FACC, FHRS
Cardiac Electrophysiology · Houston, TX · colombowala.com

Procedure

Transesophageal Echocardiogram (TEE)

An ultrasound of the heart taken from inside the esophagus, using a flexible probe similar to an upper endoscopy. The view from behind the heart is much clearer than a standard echo and lets us rule out clots before AF ablation or cardioversion.

Typical duration
30 min
Sedation
Conscious sedation, occasionally general anesthesia

Why we use TEE

A regular echocardiogram — the kind done with the probe pressed against your chest wall — gives a good general view of the heart. But the ribs, the lungs, and the chest wall itself sit between the probe and the heart, and they make some structures hard to see well.

The esophagus — the swallowing tube — sits right behind the heart. There is nothing between the two. An ultrasound probe inserted into the esophagus gives a view of the heart from behind that is dramatically clearer than what we can get from outside the chest. We see the left atrium and its appendage especially well — and that view is the central reason we order a TEE in electrophysiology.

The most common reasons for a TEE in our practice:

  • Rule out a clot in the left atrium or left atrial appendage before AF ablation or cardioversion. About 10–15% of patients with AFib carry a clot in this small pouch. Shocking or ablating a heart with a clot present can dislodge it into the bloodstream, causing a stroke. We confirm the LA is clear before proceeding.
  • Evaluate a possible source of a stroke when the standard workup hasn’t found one.
  • Look for a patent foramen ovale (PFO) — a small persistent opening between the upper chambers that can be a source of stroke in selected patients.
  • Assess prosthetic valves, vegetations on heart valves, or other structural questions when the chest-wall echo isn’t conclusive.

Before the procedure

  • NPO (no food or drink) for 6 hours before the procedure. Plain water is sometimes allowed up to 2 hours before, depending on the facility — confirm at scheduling.
  • Stop blood thinners? Usually no. We typically perform TEE on anticoagulation — that’s the whole point of confirming the atrium is clear right before the procedure that will follow. Tell us about every blood thinner you’re on so we can confirm.
  • Bring a driver. You cannot drive for the rest of the day due to the sedation.
  • Leave your dentures and any removable dental hardware at home or take them out before the procedure.
  • Bring an updated medication list including any over-the-counter products.
  • Wear comfortable clothes. You’ll change into a gown.

During the procedure

  • You’ll lie on your left side on the exam table. Vital sign monitors and IV access are placed.
  • Throat numbing — a spray of topical anesthetic is applied to the back of the throat. It tastes a bit chemical; this fades quickly.
  • Sedation — most often midazolam and fentanyl through the IV. Some patients receive propofol when deeper sedation is needed.
  • Bite block — a small plastic mouthpiece is placed to protect your teeth and the probe.
  • Probe placement — once you’re asleep, the cardiologist passes the probe through your mouth into the esophagus. Most patients have no awareness of this.
  • Imaging — the probe is positioned at several different depths to look at the heart from various angles. Total imaging time is typically 5–15 minutes.
  • Probe removal — once images are complete, the probe is gently withdrawn.

The full appointment is usually 1.5–2 hours from check-in to discharge. Active procedure time is shorter than the recovery time.

After the procedure

  • Recovery area — you’ll wake up within 15–20 minutes of the procedure ending. Most patients are alert and chatty within 30 minutes.
  • No eating or drinking until the throat numbing wears off. This is usually 60–90 minutes after the procedure. Eating before the numbing wears off carries a real risk of choking.
  • Soft foods that evening if your throat is sore. Most patients are back to normal eating by the next day.
  • No driving, no operating heavy machinery, no important decisions for the rest of the day. The amnesia effect of midazolam means many patients don’t remember anything about the procedure — including paperwork they signed in recovery.
  • Normal activity the next day.

What we tell you about the results

Most TEEs are read in real time and the cardiologist will share the key findings before you leave (or in your recovery debrief — though if you don’t remember it, we’ll send a follow-up note). The most common report:

  • “No clot seen — safe to proceed.” This is the most common result and the one we hope for. We can move forward with ablation or cardioversion as planned.
  • “Possible smoke or spontaneous echo contrast.” This is sluggish blood flow that looks hazy on the screen — not a clot, but a sign that the atrium isn’t moving blood well. We typically still proceed but with extra caution.
  • “Clot identified.” AF ablation or cardioversion is deferred. We continue or strengthen anticoagulation, repeat the TEE in 3–6 weeks, and proceed only after the clot has resolved.
  • Other findings — valve disease, prior infection, etc. — handled individually.

Common questions

Will I feel the probe? No. You’re sedated for the entire time the probe is in. The probe is removed before you wake up.

Is it the same as an upper endoscopy? Similar setup — same sedation, same kind of probe, same throat numbing — but the goals are different. Upper endoscopy looks at the stomach and the inside of the esophagus. TEE looks at the heart through the esophagus.

Why not just do a CT scan? Cardiac CT is sometimes a reasonable alternative for clot rule-out, and we do use it in selected patients (claustrophobia, severe gag reflex, esophageal pathology that makes TEE harder). TEE remains the gold standard for left atrial appendage clot assessment.

Can I drive home? No. The sedation lingers for several hours and impairs judgment more than patients realize. Plan for a ride.

What if I have a hiatal hernia / Barrett’s esophagus / prior radiation / esophageal cancer history? Bring it up before the procedure. Most patients with these conditions can still have a TEE safely, but the cardiologist will want to know.

When to call us

After the procedure, call us for:

  • Chest pain, difficulty swallowing, or unusual abdominal pain in the first 24–48 hours — these can be early signs of esophageal injury
  • Fever in the first 48 hours
  • Persistent or severe throat pain that does not improve
  • Coughing up blood or vomiting that contains blood — go to an emergency room
  • Any new neurological symptoms — weakness, numbness, vision changes, slurred speech — call 911 immediately

For most patients, TEE is uneventful — a quick procedure, a brief recovery, and the green light to proceed with the next step in their rhythm care.

Informed Consent — At a Glance

A plain-English summary of what we discuss before this procedure. This is not a substitute for the formal consent conversation with Dr. Colombowala.

Benefits

  • Detailed images of the heart's structures, particularly the left atrium and its appendage (the most common location for clots in AFib)
  • Allows us to safely proceed with AF ablation, cardioversion, or other procedures where a missed clot would risk a stroke
  • Can detect heart-source-of-stroke causes (PFO, valve vegetations, intracardiac masses)
  • Better-than-CT detail of valve function and prosthetic-valve evaluation

Risks

  • Sore throat — common, brief
  • Minor injury to the esophagus or throat — uncommon
  • Bleeding — rare; the probe is large but does not cut
  • Aspiration — very rare with appropriate fasting and sedation monitoring
  • Reaction to sedation
  • Esophageal perforation — extremely rare (about 1 in 5,000–10,000) but the most serious complication

Alternatives

  • Cardiac CT angiography of the left atrial appendage — does not require sedation, takes 10 minutes, uses radiation and contrast
  • Three weeks of documented anticoagulation before cardioversion (an alternative way to assume the LA is clot-free)
  • Cardiac MRI for some questions; not for clot rule-out in the LAA

During the procedure

You are sedated, then asked to swallow a flexible probe the diameter of a finger. The probe sits in the esophagus behind the heart and takes ultrasound images from there. You won't feel it once asleep.

Recovery

Awake in the recovery area within 15–20 minutes. No eating or drinking until the throat numbing wears off (typically 60–90 minutes after the procedure). No driving the rest of the day. Eat soft foods that evening if your throat is sore.

Related topics

Last reviewed by Dr. Colombowala on May 24, 2026.

Not medical advice. This page is educational. Reading it does not create a doctor-patient relationship. Your situation may differ — discuss it with Dr. Colombowala or your treating physician before making decisions. See the full medical disclaimer.

© 2026 Ilyas K. Colombowala, MD. All rights reserved. Reproduction, redistribution, or republication of this content in any form without written permission is prohibited.

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