For the purpose of simplicity, the focused 4-view protocol, as described by Arntfield (2015) is a rapid, but valuable approach to detecting life-threatening pathology in the critically ill. While a comprehensive TEE has over 20 views, this more refined protocol is specifically for the detection of life-threatening pathology, such as cardiac tamponade, RV failure, LV failure, and gross valvular assessment.
In the focused 4-view protocol, the 4 acoustic windows on TEE are similar to traditional TTE windows, but are essentially inverse or rotated anatomical windows. The main difference in TEE is that the transducer is centred behind the left atrium.
With the TEE probe inserted to ~30 cm and slight retroflexion, the mid-esophageal 4-chamber is shown. This is essentially an inverse image of the apical 4-chamber, but the probe is centred directly behind the left atrium. This view can be used to assess LV function/size, RV function/size, presence of pericardial effusion, and presence of massive valvular regurgitation or stenosis.
With the transducer in the same position as the view above (ME4C) but the beam advanced to ~120 to 160 degrees (through the long axis of the LV) the mid-esophageal long axis can be seen. This view provides further evidence for interrogation of the pericardium, LV function, mitral valve function, interrogation of the LV outflow tract, aortic valve and root.
The probe remains in the same position as the views above, but the beam is brought down to 90 degrees. The transducer is then rotated to the patients right to reveal the left atrium in the near field and right atrium in the far field. The IVC is seen to emerge on the left of the RA and the SVC the right of the RA. This view can be used to assess for volume status (via SVC measurements) and procedural guidance (e.g. pacemaker guidance, ECMO cannulation).
With the probe beam brought down to 0 degrees at the mid-esophagus, the transducer is advanced passed the GE junction. Slight anteflexion will bring the short axis of the of the LV and RV into visualization. This view can be used to assess LV function/size, pericardium, and for gross valvular pathology.
Arntfield R, Pace J, McLeod S, et al (2015) Focused transesophageal echocardiography for emergency physicians—description and results from simulation training of a structured four-view examination. Crit Ultrasound J 7:10. https://doi.org/10.1186/s13089-015-0027-3
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