7. Mid-Esophageal Aortic Valve Short-Axis View (ME AV SAX)
On the basis of the ME 4C view, retract the transducer until the aortic valve (AV) is centered in the field of view. Then, keep the transducer position unchanged, increase the crystal angle to 25°–45° and slightly anteflex the transducer. When the imaging plane is parallel to the AV annulus, the ME AV SAX view is obtained. The displayed anatomical structures include: left atrium (LA), interatrial septum (IAS), right atrium (RA), tricuspid valve (TV), aortic valve (AV), right ventricle (RV), and right ventricular outflow tract (RVOT). All three cusps of the aortic valve are imaged symmetrically. Slight retraction of the transducer can display the ostia of the left main coronary artery and right coronary artery.
Schematic Diagram of the ME AV SAX View
8. Mid-Esophageal Right Ventricular Inflow-Outflow Tract View (ME RV Inflow-Outflow Tract)
On the basis of the previous ME AV SAX view, increase the crystal angle to 50°–70° for imaging. The displayed anatomical structures include the left atrium (LA), interatrial septum (IAS), right atrium (RA), tricuspid valve (TV), aortic valve (AV), right ventricle (RV), right ventricular outflow tract (RVOT), and pulmonary valve (PV).
From the ME RV inflow-outflow tract view, maintain the angle at 50° to 70°, and rotate the transducer to the right (clockwise) until the tricuspid valve (TV) is centered in the image, and the bicaval TV view appears. The displayed anatomical structures include the left atrium (LA), right atrium (RA), interatrial septum (IAS), and tricuspid valve (TV).
10. Mid-Esophageal Bicaval View (ME-Bicaval)
On the basis of the previous view (ME Modified Bicaval TV), increase the imaging angle to approximately 90°–110°. The observable anatomical structures include: left atrium (LA), right atrium (RA), right atrial appendage (RAA), interatrial septum (IAS), superior vena cava (SVC), and inferior vena cava (IVC).
Schematic Diagram of the ME-2C View
11. Mid-Esophageal Left Atrial Appendage View (ME Left Atrial Appendage)
This view can be obtained by rotating the transducer to the left (counterclockwise) and slightly retracting it on the basis of the mid-esophageal bicaval view (ME-Bicaval). The displayed anatomical structures include the left atrial appendage (LAA), left atrium (LA), and left circumflex artery (LCX). In fact, the visualization of the left atrial appendage should not be limited to this single view. Especially for patients with atrial fibrillation who are scheduled to undergo radiofrequency ablation, scanning should be performed from 0° to 180°, and every angle and every view must be examined. For patients planned to undergo left atrial appendage occlusion, the measured diameters vary depending on the choice of occluder.
Schematic Diagram of the ME Left Atrial Appendage View
ME Left Atrial Appendage: The red arrow indicates the left circumflex artery (LCX).
For outpatients undergoing transesophageal echocardiography (TEE) prior to atrial fibrillation radiofrequency ablation, preoperative exploration of the left atrial appendage (LAA) shows that the complete morphology of the LAA is displayed as the transducer angle increases.
