What is done during a Transesophageal Echocardiogram (TEE)?

Transesophageal Echocardiography (TEE) Procedure

Transesophageal echocardiography (TEE) is a minimally invasive procedure that involves inserting an endoscopic ultrasound probe into the esophagus to obtain high-resolution tomographic images of the heart and great vessels. 1

Procedure Components

Pre-Procedure Preparation

• Patient is typically kept NPO (nothing by mouth) for 4-6 hours before the procedure to reduce the risk of aspiration 2
• Topical anesthetic spray is administered to the oropharynx to reduce discomfort 1
• Intravenous conscious sedation is often used to improve patient comfort during the procedure 1
• Patient's cardiovascular medications, including beta-blockers like carvedilol, are typically continued to maintain hemodynamic stability 3

Probe Insertion and Manipulation

• The TEE probe is an endoscopic device with an ultrasound transducer mounted at its tip 4
• The physician inserts the probe into the patient's esophagus and advances it to appropriate positions (approximately 25-40 cm from the teeth depending on the desired view) 2
• The probe is manipulated through multiple imaging planes to obtain different tomographic views of the heart 1
• The multiplanar probe allows for comprehensive imaging of cardiac structures from various angles 2

Imaging Acquisition

• High-frequency ultrasound waves provide detailed images of cardiac structures with superior resolution compared to transthoracic echocardiography 1
• The proximity to the heart and minimal intervening structures allows for excellent visualization of cardiac structures that may be difficult to see on transthoracic imaging 1
• Different probe positions provide specific views:
  • Low transesophageal view (probe advanced ~30 cm from teeth) 2
  • Mid transesophageal view (probe advanced ~30 cm from teeth) 2
  • High transesophageal view (probe advanced ~25-30 cm from teeth) 2
  • Transgastric subcardiac view (probe advanced ~35-40 cm from teeth) 2
  • Aortic view (probe rotated ~180°) 2

Clinical Applications

Diagnostic Applications

• Detection and assessment of endocarditis and its complications 1
• Evaluation of aortic dissection and other aortic pathologies 1
• Identification of intracardiac thrombi and other masses 1
• Assessment of valvular disorders including prosthetic valve function 1
• Evaluation of congenital heart defects 1
• Detection of cardiac sources of embolism 2
• Identification of sinus venosus atrial septal defects (visible by transthoracic imaging in only 25% of cases) 1

Procedural Guidance

• Intraoperative monitoring during cardiac surgery 1
• Guidance for catheter-based interventions 1
• Monitoring during cardioversion for atrial fibrillation/flutter 1
• Assessment before and during closure of atrial level shunts 1
• Guidance during radiofrequency ablation procedures 1

Safety Considerations

Contraindications

• Absolute contraindications include:
  • History of dysphagia 5
  • Current pathologic conditions of the esophagus 5
  • Recent esophageal operations 5
• Relative contraindications include:
  • Esophageal varices 5
  • Active upper gastrointestinal bleeding 5
  • Recent meal consumption (within 4-6 hours) 2

Complications

• Complications are rare but may include:
  • Pharyngeal and esophageal trauma 1
  • Adverse reactions to sedation 1
  • Methemoglobinemia (rare complication of benzocaine administration) 1

Advantages Over Transthoracic Echocardiography

• Higher spatial resolution than transthoracic echocardiography 1
• Unobstructed views (not limited by ribs or lungs) 1
• Superior visualization of posterior cardiac structures 1
• Better assessment of prosthetic valves, especially mitral prostheses 5
• More sensitive for detection of atrial level shunts 1
• Essential tool when transthoracic images are inadequate or non-diagnostic 1

TEE is considered a safe and valuable diagnostic tool that provides critical information for patient management in various cardiac conditions when performed by appropriately trained physicians 6.