Transesophageal echocardiography (TEE) is a type of invasive ultrasound examination of the heart and major blood vessels (aorta, pulmonary artery, pulmonary veins, superior and inferior vena cava). This type of examination is performed in patients for whom a standard non-invasive ultrasound examination (transthoracic echocardiography – TTE) does not provide sufficient information about the severity of heart disease in order to choose the best treatment approach.

The ultrasound probe used for this examination is placed inside a thin tube (endoscope) that is inserted through the mouth and throat into the esophagus.

The procedure is quite similar to a gastroenterological endoscopic examination of the esophagus and stomach, known as gastroscopy.

The advantage of this examination over standard ultrasound (TTE), which is performed through the chest wall, lies in the anatomical position of the esophagus – located directly behind the heart. This proximity allows for a much clearer and more detailed visualization of cardiac structures, including atrial and ventricular chambers, heart valves, the left atrial appendage, and major blood vessels.

INDICATIONS FOR TEE EXAMINATION

In daily clinical practice, the two most common indications for performing TEE are:

• Determining the cause of thromboembolism (after a stroke – CVI or transient ischemic attack – TIA), to detect the presence of a patent foramen ovale (PFO) and decide on further treatment.
• In the treatment of atrial fibrillation, as part of the diagnostic protocol to check for the presence of a thrombus in the left atrial appendage, in order to assess suitability for electrical cardioversion (restoring normal sinus rhythm with an electric shock).

Other important indications include:

• Evaluation of patients with valvular heart disease (congenital or acquired, such as aortic stenosis or mitral regurgitation) to assess severity and refer for cardiac surgery if needed.
• Diagnosis and evaluation of infective endocarditis (infection of native heart valves).
• Assessment of prosthetic heart valves, to evaluate their function and diagnose complications (infective endocarditis, valve thrombosis, dehiscence, or paravalvular regurgitation).
• Detection of cardiac tumors within any of the heart chambers.
• Detection of defects in cardiac septa (VSD, ASD).
• Assessment of aortic aneurysm or dissection, as part of diagnostic work-up.
• Intraoperative TEE during cardiac surgery to assess valve condition or septal integrity.

Additional reasons for performing TEE may include:

• Better visualization of heart structures in obese patients.
• When the chest is immobilized (e.g., in a cast).

HOW TEE IS PERFORMED

If the patient wears removable dentures, they must be taken out. Before the examination, an intravenous line (“butterfly needle”) is placed, usually in the right arm vein. The patient lies on their left side with ECG electrodes attached to monitor heart rhythm.

Before inserting the transesophageal probe, the back of the throat is sprayed with a local anesthetic to ease the passage of the probe. In some cases, the procedure may be performed under light sedation (analgosedation).

The patient bites a small plastic mouthguard through which the flexible endoscope is inserted. Once the tip of the probe passes the base of the tongue and reaches the back of the throat, the patient swallows to guide the probe into the esophagus.

This process and the examination itself are not painful, and breathing is not affected – the patient continues breathing normally through the mouth and nose. After the examination, the probe is carefully removed.

The duration of the procedure varies depending on the indication and patient cooperation, typically lasting 20–40 minutes.

POTENTIAL RISKS OF TEE

Possible complications during TEE include:

• Difficulty breathing
• Laryngeal spasm
• Esophageal injury or bleeding (especially in patients on anticoagulant therapy)
• Stomach injury from the probe
• Mouth, throat, or dental injury
• Irregular heart rhythm (arrhythmia)

Rarely, serious complications may occur, such as cardiac arrest or death.

PREPARATION FOR TEE

No food or drink for at least 6 hours before the procedure.

Remove any non-fixed dentures.

Avoid alcohol for several days before the exam.

Remove jewelry that might interfere with the procedure.

Empty the bladder before the exam.

Inform the doctor about any allergies (to medications, anesthetics, or latex).

Report esophageal varices, liver or gastrointestinal disease, or severe spinal deformities.

Provide a list of current medications and any cardiovascular history.

Inform the doctor if pregnant.

RECOVERY AFTER TEE

Temporary throat numbness may occur due to the anesthetic and the presence of the probe. For this reason, avoid eating or drinking for several hours after the procedure to prevent choking.

Mild throat irritation or soreness may persist for a few days, but this is rare.

In general, patients can resume normal activities a few hours after the examination.