Transesophageal echocardiography, commonly called TEE, produces detailed images of the heart by placing an ultrasound probe into the esophagus, just behind the heart itself. Because the esophagus sits so close to cardiac structures, TEE bypasses the ribs, lungs, and body wall that can degrade the quality of standard chest-surface echocardiography. The images it produces are organized into a set of standardized “views,” each angled to show specific chambers, valves, or vessels. Understanding what those views reveal, and when each one matters, is central to how clinicians diagnose heart disease, monitor surgery, and guide catheter-based interventions.
Why Standardized Views Matter
The TEE probe can rotate, flex, and advance to dozens of positions, but professional guidelines have distilled this flexibility into roughly 20 to 28 named views. Standardizing them means a cardiologist in one hospital can communicate findings to a surgeon in another using a shared visual language. It also means trainees learn a systematic sweep of the heart rather than hunting for structures ad hoc. The views fall into three broad families based on where the probe tip sits: mid-esophageal views (probe behind the left atrium), transgastric views (probe advanced into the stomach, looking upward through the diaphragm), and upper-esophageal or deep transgastric views for specific structures like the aortic arch or the left ventricular outflow tract. Each family has its own strengths and blind spots, and a thorough TEE examination typically cycles through all three.
Mid-Esophageal Views
The mid-esophageal position is where most TEE examinations begin and where the probe spends the majority of its time. From this vantage point, the ultrasound beam travels only a few centimeters to reach the left atrium, the mitral valve, and the four cardiac chambers. The mid-esophageal four-chamber view is arguably the single most recognizable TEE image: it displays both atria and both ventricles in a single frame, letting clinicians quickly compare left and right heart size, assess the mitral and tricuspid valves, and spot large pericardial effusions. In hemodynamically unstable patients, this view is one of the first acquired because it rapidly reveals whether the right ventricle is dilated or whether the left ventricle is contracting poorly.1PubMed Central. Hemodynamic assessment of critically ill patients using a miniaturized transesophageal echocardiography probe
Rotating the imaging plane from the four-chamber orientation produces additional mid-esophageal views. At roughly 60 degrees, the mitral commissural view appears, useful for pinpointing which scallop of the mitral valve is leaking. At about 90 degrees, the two-chamber view isolates the left atrium and left ventricle, showing the anterior and inferior walls. Continuing the rotation to around 120 degrees yields the long-axis view, which lines up the left ventricular outflow tract, the aortic valve, and the ascending aorta in a single sweep. This long-axis view is critical during aortic valve surgery and when evaluating obstructive conditions.
A separate mid-esophageal view focuses on the aortic valve in short axis, displaying its three cusps as they open and close. This view helps identify bicuspid anatomy, vegetations in endocarditis, and calcific degeneration. Because the atrial septum is also well seen from the mid-esophageal position, the same window is used to evaluate patent foramen ovale and atrial septal defects, often with the addition of agitated saline (“bubble study”) contrast. The mid-esophageal ascending aortic short-axis view, meanwhile, brings the superior vena cava into view, allowing assessment of its respiratory variation as a marker of fluid status.1PubMed Central. Hemodynamic assessment of critically ill patients using a miniaturized transesophageal echocardiography probe
Transgastric Views
When the probe is advanced past the gastro-esophageal junction into the stomach and anteflexed (tilted upward), the ultrasound beam enters the heart from below, through the diaphragm. This produces transgastric views, and the most widely used of these is the transgastric mid-papillary short-axis view. It shows the left ventricle in cross-section at the level of the papillary muscles, creating a donut-shaped image that divides the ventricular wall into segments corresponding to specific coronary artery territories. During cardiac surgery, this view is recorded before and after cardiopulmonary bypass to detect new wall-motion abnormalities that might signal incomplete revascularization or graft failure.2PubMed. Intraoperative detection of segmental wall motion abnormalities with transesophageal echocardiography
The transgastric short-axis view is also the standard location for calculating left ventricular fractional area change, a quick surrogate for ejection fraction that compares the ventricle’s area in systole and diastole. Because the image plane cuts cleanly through the thickest part of the ventricular wall, regional thickening or thinning is easier to spot here than in many mid-esophageal views.
Other transgastric views include the transgastric two-chamber (showing the left ventricle from apex to base along its long axis) and the deep transgastric long-axis view, which angles steeply upward through the left ventricular outflow tract and aortic valve. The deep transgastric position is one of the few TEE windows that aligns the Doppler beam parallel to blood flow across the aortic valve, making it the preferred site for measuring aortic valve gradients. In a study of coronary bypass patients, Doppler cardiac output measured from TEE views of the aortic valve correlated well with the thermodilution technique, with a correlation coefficient of 0.87 for pulsed-wave Doppler in either imaging plane.3Anaesthesia. A comparison of transoesophageal echocardiographic Doppler across the aortic valve and the thermodilution technique for estimating cardiac output
Imaging the Thoracic Aorta
The thoracic aorta runs alongside the esophagus for most of its length, making TEE an excellent tool for aortic imaging. By withdrawing the probe from the mid-esophageal level and rotating, clinicians can visualize the descending thoracic aorta in both short-axis and long-axis views, looking for dissection flaps, intramural hematomas, aneurysms, and atherosclerotic plaques. TEE can identify aortic atherosclerosis before surgical manipulation of the aorta, which is particularly important during cardiac and aortic surgery where clamping or cannulation of a diseased segment could dislodge plaque and cause stroke.4PubMed Central. Transesophageal echocardiography evaluation of the thoracic aorta
One well-known limitation is the “blind spot” in the distal ascending aorta and proximal aortic arch, where the air-filled trachea and left mainstem bronchus sit between the esophagus and the aorta, scattering the ultrasound beam. This gap can hide short-segment dissections or plaques in that region, and clinicians working up acute aortic syndromes sometimes supplement TEE with CT angiography to cover it. The rest of the thoracic aorta, however, is seen with high resolution and in real time, which is why TEE has become a go-to bedside tool for diagnosing acute aortic emergencies and for monitoring endovascular aortic repairs, where detection of endoleaks requires immediate imaging.4PubMed Central. Transesophageal echocardiography evaluation of the thoracic aorta
Guiding Catheter-Based Interventions
TEE views have taken on an expanded role as structural heart interventions have grown more common. During transcatheter mitral valve repair with edge-to-edge clip devices, for instance, TEE is not just a monitoring tool but a navigation system. The interventionalist relies on specific views at every step: a bicommissural view to position the clip along the line of coaptation, a long-axis view to confirm both the anterior and posterior leaflets are visible alongside both clip arms, and color Doppler views to judge whether regurgitation has been reduced enough. The long-axis view showing both leaflets and both clip arms is considered the most critical image during grasping, and proceeding without a high-quality version of it is discouraged.5Structural Heart. Echocardiographic Guidance of Transcatheter Mitral Valve Edge-To-Edge Repair
After grasping, the decision to release or reposition the clip hinges on three TEE-derived findings: whether the leaflets are securely captured, whether regurgitation has decreased, and whether the clip has created too much narrowing of the valve opening (mitral stenosis). These assessments all happen in real time, cycling through multiple mid-esophageal and transgastric views within seconds.5Structural Heart. Echocardiographic Guidance of Transcatheter Mitral Valve Edge-To-Edge Repair
TEE also plays a central role in imaging prosthetic paravalvular leaks, where blood slips around the sewing ring of a replacement valve. Two- and three-dimensional TEE views are used to locate and size the leak channel, guide percutaneous closure devices into position, and confirm afterward that the leak has been sealed.6PubMed Central. Cardiac imaging in prosthetic paravalvular leaks
Three-Dimensional and Multiplanar Reconstruction
Modern TEE probes can acquire a pyramidal volume of ultrasound data rather than a single flat slice, enabling live three-dimensional (3D) imaging. The most widely used 3D format in clinical practice is the “en face” view of a valve, which shows the structure as if you were looking directly at it from the atrial or ventricular side. This perspective is intuitive for surgeons planning a repair, because it closely matches what they will see once the heart is opened.
A refinement called live 3D multiplanar reconstruction (MPR) displays multiple simultaneous two-dimensional slices through the 3D volume, along with the 3D en face image, all updating in real time. During mitral and tricuspid valve clip procedures, 3D MPR allows the imaging team to see the clip alongside the valve leaflets in two different mid-esophageal planes at once, reducing the need to reposition the probe between mid-esophageal and transgastric windows. It also helps correct for parallax errors that can occur when measurements are taken from a 3D rendering alone; by cross-referencing with the two-dimensional slices, the team can confirm that the imaging plane truly passes through the intended structure.7PubMed Central. Live Three-Dimensional Multiplanar Reconstruction Imaging Guidance for Concomitant Mitral and Tricuspid Valve Repairs Using the MitraClip
When more than one clip is deployed, 3D MPR is particularly useful because it lets the operator distinguish between the previously placed clip and the one currently being positioned. The imaging planes can be adjusted on the fly to follow the device as it moves, locate the area of greatest regurgitation, and guide the clip into that spot with the correct orientation relative to the valve.7PubMed Central. Live Three-Dimensional Multiplanar Reconstruction Imaging Guidance for Concomitant Mitral and Tricuspid Valve Repairs Using the MitraClip
TEE for Endocarditis and Other Diagnostic Challenges
Infective endocarditis, an infection of the heart valves or endocardial surface, is one of the clearest examples of a diagnosis where TEE outperforms transthoracic echocardiography (TTE). While TTE is the first-line test, TEE is recommended whenever TTE is non-diagnostic, when complications like abscess formation are suspected, or when intracardiac device leads (such as pacemaker wires) are present. TEE’s superior resolution allows it to characterize the size, shape, mobility, and attachment point of vegetations, all of which influence the risk of embolism and the decision about whether surgery is needed.8PubMed Central. Infective Endocarditis: Echocardiographic Imaging and New Imaging Modalities
The sensitivity of TEE for detecting vegetations exceeds that of TTE by a wide margin, particularly for prosthetic valve endocarditis and for small vegetations under 5 mm. Mid-esophageal views of the mitral and aortic valves are the primary windows, but transgastric views can add information when vegetations are located on the ventricular side of the valve or when the acoustic angle from the esophagus is suboptimal.
Safety and Complications
TEE is considered a semi-invasive procedure. The probe must pass through the mouth and pharynx, and patients typically feel pressure and sometimes gagging during insertion. Serious complications are uncommon but worth knowing about. A large systematic review and meta-analysis pooling data from studies covering more than 64,000 procedures estimated the overall adverse event rate at about 0.65%. Bleeding was the most frequently reported complication at around 0.17%, followed by swallowing difficulty (dysphagia) at about 0.27%. Esophageal perforation, the most feared complication, occurred in roughly 0.01% of cases.9Cardiologia Hungarica. Esophageal perforation and other procedural complications of transesophageal echocardiography: A comprehensive systematic review and meta-analysis (2000–2025)
There was substantial variability across clinical settings, which makes sense given that the risk profile of a TEE performed on a sedated outpatient differs from one performed on a critically ill patient on a ventilator. Patients with known esophageal disease, prior esophageal surgery, or significant cervical spine abnormalities carry higher risk, and many centers consider these relative or absolute contraindications. A careful history and, in some cases, a prior esophageal examination can help identify those at elevated risk before the probe is inserted.
Sedation Approaches
Outside the operating room, TEE is usually performed under conscious sedation rather than general anesthesia. The goal is to suppress the gag reflex and keep the patient comfortable enough to tolerate the probe while still breathing independently. A common approach combines a topical anesthetic spray to the throat with intravenous midazolam, a short-acting sedative. In one cohort, a median midazolam dose of 2 mg was administered, with lower starting doses for patients over 75 years old. About 84% of patients also received an opioid (pethidine) alongside the midazolam, and the majority reached a moderate level of sedation before probe insertion.10British Journal of Cardiology. Safe combined intravenous opiate/benzodiazepine sedation for transoesophageal echocardiography
Newer protocols have explored alternatives. A trial comparing alfentanil combined with dexmedetomidine against a midazolam-based regimen found that the alfentanil-dexmedetomidine combination achieved a successful initial sedation rate of 85%, compared with 35% for the midazolam group. It also resulted in less hypotension. The tradeoff was a higher rate of mild respiratory depression, though no episodes of actual low oxygen levels or airway compromise occurred in either group, and recovery time was shorter with the alfentanil-dexmedetomidine protocol.11PubMed. Application of Alfentanil Combined With Dexmedetomidine for Conscious Sedation of Patients During Transesophageal Echocardiography Examination
In the operating room, TEE is performed under general anesthesia as part of the surgical anesthetic, so sedation is a non-issue. The probe is placed after intubation and stays in for the duration of the procedure. Intraoperative TEE is routine in most cardiac surgeries and is increasingly used in selected non-cardiac surgeries where hemodynamic monitoring is warranted.
Common Artifacts and Interpretation Pitfalls
Like all ultrasound modalities, TEE is susceptible to imaging artifacts that can mimic pathology or obscure genuine findings. Reverberations, where the ultrasound beam bounces between two strong reflectors and creates ghost images, are among the most common. A classic example occurs in the ascending aorta, where a reverberation artifact from the posterior aortic wall can produce a linear echo inside the aortic lumen that mimics a dissection flap. Distinguishing artifact from true pathology requires checking multiple views, adjusting the probe angle, and looking for associated findings like a true and false lumen with different flow patterns on color Doppler.
Near-field clutter and side-lobe artifacts can create spurious echoes within the left atrium that resemble thrombus or mass. Calcified structures, mechanical prosthetic valves, and surgical pledgets all generate acoustic shadowing that can hide structures behind them. Three-dimensional imaging introduces its own set of artifacts, including “stitching artifacts” when the 3D volume is assembled from multiple heartbeats that do not align perfectly, and dropout artifacts where parts of a valve appear to be missing because the ultrasound beam did not reach them at sufficient strength.
Normal anatomical variants also trip up less experienced readers. The Coumadin ridge (a fold of tissue between the left upper pulmonary vein and the left atrial appendage), the Eustachian valve (a remnant at the junction of the inferior vena cava and the right atrium), and a prominent Chiari network can all be mistaken for pathological masses or vegetations. Familiarity with these variants is part of the learning curve for TEE interpretation.
AI and Automated View Classification
A typical cardiac surgery generates hundreds of TEE video clips, and sorting through them manually is tedious. Recent work in deep learning has shown that convolutional neural networks can classify standard TEE views with high accuracy. A model trained on labeled intraoperative videos achieved strong performance across multiple view categories, with particularly high accuracy for the transgastric left ventricular short-axis view and the mid-esophageal long-axis and four-chamber views. When externally validated on videos from a different medical center, performance remained high, suggesting the models generalize beyond the data they were trained on.12Scientific Reports. Deep learning for transesophageal echocardiography view classification
Building on view classification, researchers have started developing integrated automated frameworks that go beyond simply naming the view. A proof-of-concept system trained on more than 700,000 individual TEE clips combined view classification with automated assessment of left ventricular ejection fraction, right ventricular function, and tricuspid regurgitation grading. The view classifier in this system reached 86% accuracy, which actually exceeded the 74% top-choice agreement rate among the expert echocardiographers who labeled the data, a reminder that even experienced readers do not always agree on which standard view a given clip best represents.13PubMed Central. Proof-of-Concept Automated Framework for Intraoperative Transesophageal Echocardiography: View Classification and Biventricular Function Assessment
These tools are not ready to replace human interpretation, but they point toward a future where routine measurements could be extracted automatically from intraoperative TEE recordings. The most likely near-term application is retrospective: automatically organizing and indexing the massive archive of TEE studies that hospitals accumulate, making it searchable for quality improvement, research, and training. Real-time intraoperative decision support is a more ambitious goal and will require further validation in clinical settings where the stakes are highest.
Miniaturized and Point-of-Care TEE Probes
Standard TEE probes are roughly the diameter of a large adult finger, which limits their use in certain populations and settings. In recent years, miniaturized TEE probes have been developed that are thin enough to remain in place for extended monitoring in critically ill patients, sometimes for hours, without the same level of sedation required for a full-sized probe. These smaller probes sacrifice some image quality and the ability to acquire every standard view, but they can reliably obtain a subset of views sufficient for answering focused clinical questions: Is the left ventricle squeezing well? Is the right ventricle dilated? Is the patient volume-depleted? In hemodynamically unstable patients, three views obtained with a miniaturized probe, including a transgastric short-axis view for ventricular function, a mid-esophageal four-chamber view for right ventricular size, and a mid-esophageal view of the superior vena cava for volume assessment, provided the information needed to guide resuscitation.1PubMed Central. Hemodynamic assessment of critically ill patients using a miniaturized transesophageal echocardiography probe
This focused approach represents a philosophical shift. Rather than performing a comprehensive 28-view examination, the clinician acquires only the views needed to answer a specific hemodynamic question. It blurs the line between a formal echocardiographic study and a point-of-care assessment, and it has expanded TEE use into intensive care units and emergency departments where it was once rare. As probe technology continues to shrink and image processing improves, the range of clinical environments where TEE views can be acquired will keep growing.