When is transesophageal echocardiography (TEE) recommended for cardiac imaging?

When is Transesophageal Echocardiography (TEE) Recommended?

TEE is recommended as the first-line imaging modality when high-risk cardiac pathology requiring superior visualization could be missed by transthoracic echocardiography (TTE), particularly for acute aortic syndrome, prosthetic valve dysfunction, endocarditis, cardiac source of embolism, and when TTE is expected to be non-diagnostic due to patient factors like mechanical ventilation or recent cardiac surgery. 1

Primary Indications Where TEE Should Be First Choice

Life-Threatening Conditions Requiring Superior Visualization

TEE should be the initial test when missing the diagnosis carries high morbidity and mortality, including:

• Acute aortic syndrome (dissection, transection) where rapid diagnosis is critical 1
• Acute valvular regurgitation requiring immediate surgical decision-making 1
• Acute prosthetic valve dysfunction where detailed valve assessment is essential 1
• Acute massive pulmonary embolism to guide thrombolytic therapy 1
• Chest trauma with suspected aortic transection 1

Cardioversion Planning

• Symptomatic atrial fibrillation/flutter when cardioversion is planned to exclude left atrial appendage thrombus 1, 2
• Atrial flutter lasting >48 hours without adequate anticoagulation prior to cardioversion 2

Cardiac Source of Embolism

• Cryptogenic stroke evaluation where paradoxical embolism through patent foramen ovale (PFO) is suspected 3, 4
• TEE provides 51% sensitivity versus 32% for TTE in detecting intracardiac shunts 3
• Superior visualization of left atrial appendage, atrial septum, and potential embolic sources 5, 4

Endocarditis Assessment

• Suspected infective endocarditis, particularly for:
  • Prosthetic valve endocarditis 4
  • Native valve endocarditis when TTE is non-diagnostic 4
  • Detection of vegetations and complications (abscess, perforation) 6

TEE as Second-Line After Non-Diagnostic TTE

Patient Factors Predicting Poor TTE Quality

TEE should follow TTE when suboptimal images are expected based on:

• Mechanical ventilation in ICU patients 1
• Recent post-operative cardiac surgery with chest wounds 1, 6
• Severe chest wall deformation or injury 1
• Severe COPD or lung emphysema 1
• Intraprocedural or intraoperative monitoring 1

Structures Best Visualized by TEE

TEE provides superior imaging of:

• Mitral valve apparatus including leaflet morphology and regurgitation severity 1, 5
• Left atrial appendage for thrombus detection 5, 4
• Atrial septum for PFO, atrial septal defect sizing, and rim assessment 3, 5
• Thoracic aorta throughout its course 5, 4
• Prosthetic valves, particularly mitral position 1, 4

Critical Care and Emergency Settings

Hemodynamic Instability

TEE is valuable in ICU when TTE is inadequate for:

• Unexplained hypotension or shock requiring rapid diagnosis 1, 7
• Post-cardiac surgery complications (tamponade, valve dysfunction, ventricular dysfunction) 1, 7, 6
• Respiratory failure with suspected cardiac etiology 1

In one ICU study, TEE diagnosed 131 significant findings versus only 95 (73%) found by TTE, with particular superiority in detecting mitral regurgitation (9% additional cases, p<0.05) 6

Procedural Guidance

TEE is essential for real-time guidance during:

• Transcatheter aortic valve replacement (TAVR) for annular sizing, positioning, and complication detection 1
• MitraClip procedures requiring precise anatomic measurements and device positioning 1
• Percutaneous septal defect closures 1, 4
• Catheter ablation procedures 1, 4

Important Caveats and Limitations

TEE Blind Spots

Be aware that TEE has specific anatomic limitations:

• Right ventricular outflow tract and pulmonary valve are poorly visualized 3
• Distal right pulmonary artery and proximal left pulmonary artery 3
• Apical-anterior septum may be obscured 3
• Areas masked by prosthetic material 3

Contraindications

Absolute contraindications include:

• Esophageal pathology (stricture, varices, tumor, recent surgery) 4
• Active upper GI bleeding 4
• Uncooperative patient without sedation capability 4

Relative contraindications:

• Recent meal within 4-6 hours (aspiration risk) 4
• Severe coagulopathy 7
• Large hiatal hernia (may limit transgastric views) 7

Safety Profile

Serious complications are very rare (3-5% unsuccessful due to probe intolerance, 4-5% require general anesthesia) 3, 4

Practical Algorithm for TEE Ordering

Order TEE as first test when:

1. Suspected acute aortic syndrome, prosthetic valve dysfunction, or endocarditis
2. Planning cardioversion for atrial fibrillation/flutter >48 hours
3. Patient is mechanically ventilated or immediate post-cardiac surgery
4. Guiding transcatheter interventions

Order TEE after non-diagnostic TTE when:

1. TTE image quality inadequate due to body habitus, COPD, or chest wall factors
2. Detailed assessment of mitral valve, left atrial appendage, or atrial septum needed
3. Evaluating cardiac source of embolism after stroke/TIA
4. Assessing prosthetic valve function when TTE inconclusive

Do not order TEE when:

1. TTE provides diagnostic information sufficient for clinical decision-making
2. Esophageal contraindications present
3. Findings would not change management