A transesophageal echocardiogram (TEE) is performed when your doctor needs a clearer, more detailed view of your heart than a standard echocardiogram can provide. Because the imaging probe sits in your esophagus, just behind the heart, it produces sharper images of structures that are harder to see from outside the chest. It’s not the first test most people get. A regular echocardiogram, done by pressing a probe against your chest wall, works well for many conditions. TEE is reserved for situations where that standard view isn’t enough or where specific structures need close-up examination.
Why TEE Gives a Better Picture
A standard echocardiogram sends ultrasound waves through your skin, ribs, and lungs before they reach the heart. All that tissue can scatter the signal and reduce image quality. A TEE skips those barriers entirely. The esophagus runs directly behind the heart, so placing a small ultrasound probe there puts it just millimeters from the structures that matter most, particularly those at the back of the heart that face away from the chest wall.
This positioning makes TEE especially good at visualizing the left atrial appendage (a small pouch where blood clots commonly form), the heart valves, the wall between the heart’s upper chambers, and the aorta. For these structures, TEE isn’t just slightly better. In some cases, conditions visible on TEE are virtually undetectable on a standard echo.
Checking for Blood Clots Before a Procedure
One of the most common reasons for a TEE is to look for blood clots in the heart before a procedure like cardioversion (an electrical reset of your heart rhythm) or catheter ablation for atrial fibrillation. When your heart quivers instead of pumping effectively, blood can pool and clot in the left atrial appendage. If a clot is sitting there when your heart rhythm is restored, it can break loose and travel to the brain, causing a stroke.
Guidelines recommend either three weeks of blood-thinning medication before cardioversion or a TEE to confirm no clot is present so the procedure can happen sooner. Even among patients who have been properly anticoagulated, clots still show up in about 2.7% of cases. In patients with inadequate anticoagulation, that number jumps to as high as 23%. A standard echo simply cannot see the left atrial appendage well enough to rule out a clot, making TEE essential for this purpose.
Finding the Source of a Stroke
After a stroke or transient ischemic attack (TIA), doctors often need to find out whether a clot originated in the heart. TEE is far more effective at this than a standard echo. Research published by the American Heart Association found that in patients whose standard echo looked completely normal, TEE still detected a cardiac source of embolism in roughly 40% of cases, regardless of the patient’s age.
TEE is particularly valuable for spotting clots in the left atrial appendage, clots on the aorta, holes between the heart’s upper chambers (patent foramen ovale), and bulging of the wall between the atria. These findings directly change treatment decisions, often leading to blood-thinning therapy that can prevent a second stroke.
Detecting Heart Valve Infections
Infective endocarditis, a serious infection of the heart valves, is diagnosed primarily through a combination of blood cultures and echocardiography. TEE plays a central role because it can reveal small clusters of bacteria and debris (called vegetations) growing on valve surfaces, abscesses forming around valves, and holes that infection has eaten through valve tissue. While a standard echo can sometimes detect these problems, TEE’s higher resolution makes it the preferred tool when endocarditis is suspected but initial testing is inconclusive, or when complications like abscess formation need to be assessed.
Diagnosing Holes in the Heart
TEE with a bubble study is the gold standard for diagnosing a patent foramen ovale (PFO), a small flap-like opening between the heart’s upper chambers that failed to close after birth. During the test, a saline solution mixed with tiny air bubbles is injected into a vein. If a PFO is present, the bubbles cross from the right side of the heart to the left and can be seen on the ultrasound image.
Newer three-dimensional TEE takes this a step further, allowing doctors to watch the bubbles pass directly through the opening in real time. This helps distinguish a PFO from other types of shunts, such as abnormal blood vessel connections in the lungs, which can look similar on a standard two-dimensional study. In some patients, 3D TEE has revealed complex anatomy, like two separate openings in the same PFO, that would be difficult to appreciate any other way.
Guiding Heart Surgery and Procedures
TEE is routinely used in the operating room during open-heart surgery, valve repairs, and catheter-based procedures. Surgeons rely on real-time TEE images to assess valve function before and immediately after a repair, guide catheters into precise positions, and confirm that a device (like a closure plug for a PFO) is seated correctly. In these settings, the patient is already under general anesthesia, so the TEE probe can remain in place throughout the procedure without any added discomfort.
What the Procedure Feels Like
The entire appointment typically takes up to 90 minutes, though the actual imaging portion lasts only about 15 minutes. Before the probe goes in, your throat is sprayed with a numbing agent to prevent gagging, and you receive a sedative through an IV. Most people are awake but drowsy and relaxed. General anesthesia is rarely needed for a diagnostic TEE, but if it is used, you’ll be fully asleep and won’t remember the procedure.
The probe is about the width of a finger and is gently guided down your throat into your esophagus. You may feel pressure or a mild urge to gag as it passes, but the sedation and numbing spray minimize discomfort. Your heart rate, blood pressure, and oxygen levels are monitored throughout.
Risks and Complications
TEE is considered safe, but it is more invasive than a standard echo, which is why it’s only used when the added image quality is genuinely needed. Major complications, including esophageal injury or significant bleeding, occur in 0.2% to 0.5% of cases. One study that tracked patients for delayed problems estimated gastrointestinal injuries at about 1.2%. The risk of significant gastrointestinal bleeding specifically falls between 0.02% and 1.0%.
Certain conditions make TEE unsafe. A history of difficulty swallowing, esophageal tumors, tears or perforations in the esophagus, and recent esophageal surgery are all absolute reasons not to perform the test. Esophageal varices (swollen veins in the esophagus, often related to liver disease) and active upper gastrointestinal bleeding are relative contraindications, meaning the doctor weighs the risk against the diagnostic benefit before proceeding.
After the Test
The sedative wears off fairly quickly, but you’ll feel groggy for a while. You won’t be able to drive yourself home, so plan to have someone with you. Your throat will likely feel sore or scratchy for the rest of the day. You’ll need to wait until the numbing spray fully wears off before eating or drinking, since swallowing reflexes are temporarily dulled and there’s a small risk of choking. Most people resume normal activities by the following day.