II. Indication
- Suspected Pulmonary Embolism
- Patients too unstable to undergo CT PE study
- McConnell Sign (dilated RV, RV free wall akinesis, normal apical contractions)
-
Aortic Dissection
- Aortic Dissection assessment (consider CT angiogram as alternative)
- Thoracic Aortic Aneurysm
- Valvular heart disease (including small valvular vegetations)
- Left atrial thrombus
-
Cardiac Arrest
- Heart and Great Vessels are seen without chest wall or epigastric bowel gas obstruction
- May be monitored without interruption and not interfere with Resuscitation efforts
- Heart function and compression quality can be accurately monitored
- Distinguishes cardiac standstill (true PEA or Asystole) from ineffective contraction
- May identify Cardiac Tamponade, PE with RV strain, vascular rupture
III. Contraindications
- Severe esophageal stenosis
- Tracheoesophageal fistula
- More common in gastrostomy Feeding Tube
IV. Technique: Scope
- Assumes Conscious Sedation or Endotracheal Intubation
- TEE is inserted and steered in similar fashion to bronchoscope, Nasolaryngoscopy or endoscope
- Multiplane Ultrasound transducer lies in the scopes flat head
- Transducer direction is manipulated with thumb pad on scope handle
- Examiner hand positions
- Examiner holds scope with non-dominant hand by patients mouth to insert, secure or withdraw the tube
- Examiner uses dominant hand to hold the scope handle and manipulate the transducer direction
- Key Views (see below)
- Mid-Esophageal Four-Chamber View (MEFC View)
- Transgastric Mid-Papillary Short-Axis View (TGMPSA)
V. Imaging: Mid-Esophageal Four-Chamber View (MEFC View)
- Positioning
- Visualized on initial probe insertion
- Multiplane transducer angle set to 0 degrees (no rotation)
- Landmarks
- Four chamber view (only part of right atrium visualized)
- Mitral and tricuspid valves
- Interventricular septum and apex
VI. Imaging: Transgastric Mid-Papillary Short-Axis View (TGMPSA View)
- Positioning
- Scope inserted into Stomach, and then retro-flexed (or anteflexed) up toward the heart
- Scope is withdrawn in this J-tip position until the left ventricle comes into view
- Landmarks
- Coronary arteries
- Left ventricle (in cross section, appears as doughnut)
- Pericardium (and Pericardial Effusion)
VII. Imaging: Mid-Esophageal Long Axis View (MELA View)
- Positioning
- Scope at mid-Esophagus depth
- Multiplane transducer rotation angle set to 120 degrees (toward LV outflow tract)
- Landmarks
- Left ventricular inflow via mitral valve
- Left ventricular outflow via aortic valve
- Proximal aorta (and Aortic Dissection or dilitation)
VIII. Imaging: Mid-Esophageal Bicaval View (MEBC View)
- Positioning
- Scope at mid-Esophagus depth, rotated toward patient right (clockwise)
- Multiplane transducer rotation angle set similarly to MELA View (120 degrees) +/- 20 degrees
- Landmarks
- Right atrium with inflow from superior and inferior vena cava
- Interatrial septum and left atrium
IX. Efficacy
-
Aortic Dissection
- Sensitivity: 97%
- Specificity: 75-90%
X. Advantage
- Sensitive for hemodynamically significant emboli
- Less invasive
- Fast
- Widely available
XI. Disadvantage
- Requires sedation
- Misses small Pulmonary Emboli (only 13% sensitive)
- Requires sedation and trained technician
-
False Positives in the Cardiac Arrest setting
- For patients undergoing ROSC, confirm TEE findings
XII. References
- O'Rourke, Denson, Mendenhall, Fox (2018) Crit Dec Emerg Med 32(4): 19-25