What are the standard views and procedure for performing transesophageal echocardiography (TEE)?

From the Guidelines

Transesophageal echocardiography (TEE) is performed using five standard views: midesophageal four-chamber, midesophageal two-chamber, midesophageal long-axis, transgastric short-axis, and the aortic arch view. The procedure begins with patient preparation including NPO status for 6 hours, informed consent, and assessment for contraindications such as esophageal strictures or recent esophageal surgery 1. Topical anesthesia with lidocaine spray (10%) is applied to the oropharynx, followed by conscious sedation typically using midazolam (1-2 mg IV) and fentanyl (25-100 mcg IV) titrated to effect. Supplemental oxygen should be provided and vital signs monitored continuously. The patient is positioned in the left lateral decubitus position with the head flexed forward. The TEE probe is lubricated and gently advanced into the esophagus at approximately 30-40 cm from the incisors, then manipulated using anteflexion, retroflexion, and rotation to obtain the standard views.

The examination should systematically assess cardiac chambers, valves, great vessels, and pericardium. Key aspects to evaluate include:

• Cardiac chamber sizes and function
• Valvular structure and function, including detection of regurgitation or stenosis
• Presence of intracardiac thrombi or other masses
• Aortic pathology, such as dissection or aneurysm
• Evaluation of prosthetic valve function

Following the procedure, patients should be monitored until sedation effects wear off and should not drive or operate machinery for 24 hours. The procedure allows for superior visualization of posterior cardiac structures compared to transthoracic echocardiography due to the proximity of the esophagus to the heart without interference from lung or chest wall tissue. As noted in the guidelines, TEE is a minimally invasive procedure with small but definite risks, and it should be reserved for clinical circumstances in which the potential findings have significant implications for patient management and cannot be obtained by transthoracic evaluation 1.

In the context of transcatheter interventions for valvular heart disease, TEE can play a crucial role in guiding the procedure, particularly in positioning the balloon and prosthesis, detecting complications, and assessing prosthesis function immediately post-implantation 1. However, the use of peri-procedural TEE may require general anesthesia and could partially obstruct the fluoroscopic view, which are considerations in deciding its application.

From the Research

Standard Views for Transesophageal Echocardiography (TEE)

The standard views for TEE include:

• Low transesophageal view (the probe is advanced approximately 30 cm from the teeth) 2
• Mid transesophageal view (the probe is advanced approximately 30 cm from the teeth) 2
• High transesophageal view (the probe is advanced approximately 25-30 cm from the teeth) 2
• Transgastric subcardiac view (the probe is advanced approximately 35-40 cm from the teeth) 2
• Transgastric five-chamber view (the probe is advanced deeper than in the subcardiac view and with a stronger anterior flexion of the probe) 2
• Aortic view (the probe should be rotated at about 180°) 2

Procedure for Performing TEE

The procedure for performing TEE involves:

• Advancing the probe to the desired position based on the indication for the examination 2
• Rotating the probe to obtain the desired imaging plane 2
• Assessing cardiac structures systematically, including the mitral valve, left atrial appendage, and interatrial septum 3
• Using a standardized approach to ensure comprehensive assessment of cardiac structures 3
• Acquiring additional views as needed to improve assessment of specific cardiac structures, such as the right heart 4

Indications for TEE

TEE is indicated for:

• Assessment of cardiac source of embolism 2
• Suspected endocarditis 2
• Suspected prosthetic valve dysfunction 2
• Assessment of thoracic aorta and other vessels 2
• Assessment prior to valvular repairs and closures of septal defects 2
• Intraoperative monitoring of cardiac or percutaneous interventions 2
• Ablation 2
• Non-diagnostic transthoracic examination, especially in patients after cardiac surgeries 2

Technical Considerations

TEE should be performed:

• In an appropriately accredited laboratory 2
• By a cardiologist with individual accreditation 2
• Using a multiplanar probe to ensure the best conditions for imaging of the heart and thoracic aorta 2
• With patient consent 2
• With consideration of potential complications, such as esophageal perforation and massive gastrointestinal bleeding 2