Midesophageal Four Chamber

The ME four-chamber view is obtained by advancing the probe to a depth of 30 to 35 cm until it is immediately posterior to the LA. The omniplane angle is adjusted to 0° to 20°, and the probe is rotated clockwise or counterclockwise to center the mitral valve and LV in the sector display. The LA, LV, RA, and RV should be visualized in this view. If the LVOT is visualized (an anterior structure), then the probe should be retroflexed.

The ME four chamber is extremely useful for evaluating chamber size, ventricular function, and tricuspid and mitral valvular function. Color flow Doppler over the valves is used to assess stenosis and regurgitation. Of note, the LV inferoseptal and anterolateral (AL) walls are seen in this view; new wall motion abnormalities (eg, hypokinesis, akinesis or dyskinesis) in these regions can reflect ischemia of the right coronary artery (RCA) or left anterior descending (LAD), respectively.

Midesophageal Two Chamber

From the ME four-chamber view, the omniplane angle is increased to 80° to 100° to achieve the ME two-chamber view. This view shows the LA and LA appendage, MV, LV (inferior and anterior walls), and coronary sinus (in cross-section immediately below the basal inferior segment of the LV).

Color flow Doppler over the MV may reveal stenosis or regurgitation. New regional wall motion abnormalities of the basal and mid-inferior wall can indicate ischemia of the RCA. New regional wall motion abnormalities in the apical and anterior wall segments can indicate LAD ischemia.

Midesophageal Long Axis

From the ME two-chamber view, omniplane angle is increased to 120° to 160°. The LAX view displays the LA, MV, LV (anteroseptal and inferolateral walls), LVOT, AV, and proximal ascending aorta. This view provides useful information regarding chamber volume; LV, MV, and AV function; and LVOT and proximal aortic pathology. Regional wall motion abnormalities can indicate ischemia of the RCA or left circumflex coronary artery (LCX) (basal inferolateral and mid inferolateral walls) or LAD (apical, mid- and basal anteroseptum). Color flow Doppler across the MV, LVOT, and AV can help diagnose stenosis, regurgitation, or LVOT obstruction (eg, due to ventricular hypertrophy and systolic anterior motion [SAM] of the MV).

Midesophageal Ascending Aortic Long Axis

The ME ascending aortic LAX view is obtained by withdrawing the probe from the ME LAX view. This view provides an image of the ascending aorta in LAX, as well as the right PA (in SAX). Aortic dissection and atherosclerotic plaque can be observed in this view, as can pulmonary emboli in the right PA.

Midesophageal Ascending Aortic Short Axis

From the ascending aortic LAX view, the ominplane angle is reduced to 20° to 40° to achieve the ME ascending SAX view. This view shows the ascending aorta in SAX, with the main PA on the right of the image and the right PA behind the aorta (closer to the probe). The superior vena cava (SVC) is also visualized in SAX on the left side of the image. This view can reveal a type A aortic dissection or proximal or saddle pulmonary emboli.

Midesophageal Aortic Valve Short Axis

From the ME ascending aortic SAX view, the probe is advanced to obtain the SAX AV view. Assuming a trileaflet valve, the left coronary cusp is posterior and on the right side of the screen. The right coronary cusp is anterior, adjacent to the RV and RVOT. The noncoronary cusp is adjacent to the interatrial septum. This view can identify congenital or acquired valvular abnormalities, such as a bicuspid AV or calcified and restricted valve leaflets. Color flow Doppler over the valve will identify aortic regurgitation, visible as a region of color across the cardiac cycle.

Midesophageal Right Ventricular Inflow-Outflow

From the prior view, the RV inflow-outflow view is obtained by advancing the probe, rotating slightly clockwise, and increasing the omniplane angle to 60° to 80°. The LA is closest to the probe; the RA is on the left of the screen, the RV in the middle, and the RVOT on the right of the screen. This view is useful for evaluating the tricuspid and pulmonic valves, and the systolic function of the right ventricle. Color flow Doppler can help identify tricuspid or pulmonic regurgitation or (less commonly) stenosis.

Midesophageal Bicaval

This view can be obtained by rotating the probe clockwise from the RV inflow-outflow view and increasing the omniplane angle to 90° to 110°. This view shows the SVC (on the right of the screen), the LA, RA, and RA appendage in the middle of the screen, and the inferior vena cava on the left of the screen. This view is useful for identifying correct (venous) placement of new central line wires and catheters, as well as preexisting pacemakers or other devices. Color flow Doppler at a low Nyquist setting (30 cm/s) may identify shunts across the interatrial septum, as can an injection of agitated saline ("bubble study").

Transgastric Midpapillary Short Axis

This view is obtained by advancing the probe from the ME four-chamber view, with 0° omniplane, into the stomach. The probe is then anteflexed to achieve contact with the gastric wall. The appropriate depth is determined by the visualization of the AL and posteromedial PM. The PM is typically at the 12 to 2 o'clock position on the LV, and AL PM at roughly 5 o'clock. Visualization of chords or mitral valve leaflets indicates that the probe should be advanced and/or anteflexion decreased; if no PMs are seen, then the probe is likely too deep or anteflexion inadequate.

This view is extremely useful for evaluating biventricular size and function, LV regional wall motion abnormalities, volume status, and pericardial effusion. Importantly, this is the only view in which LAD, LCX, and RCA territories can be simultaneously evaluated, albeit at a single level. The inferoseptal wall is perfused by the RCA or the LAD; the inferolateral wall by the RCA or the LCX; the anteroseptal and anterior wall segments by the LAD; and the AL wall by the LAD or the LCX. New wall motion abnormalities in any of these territories can indicate myocardial ischemia. Finally, intraventricular septal flattening during systole and diastole can indicate RV pressure or volume overload, respectively.

Descending Aortic Short Axis

The descending aorta is easily imaged by TEE, as the vessel lies adjacent and to the left of the esophagus. From the ME four-chamber view, the probe is rotated counterclockwise until the aorta appears in SAX. The probe may then be advanced and withdrawn to image the full length of the descending aorta. Type B aortic dissections, aortic aneurysms, and atherosclerotic disease can be diagnosed in this view. Left pleural effusions can also be seen.

Descending Aortic Long Axis

The descending aortic LAX view is obtained from the SAX view, described previously, by rotating the multiple to approximately 90°, such that the ultrasound beam is parallel to the vessel. The right side of the screen indicates the proximal descending aorta.

References

• Reeves ST, Finley AC, Skubas NJ, et al. Council on Perioperative Echocardiography of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. Special article: basic perioperative transesophageal echocardiography examination: a consensus statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. Anesth Analg. 2013;117:543-558.
• Vegas A. TEE views. In: Vegas A, ed. Perioperative Two-Dimensional Transesophogeal Echocardiography: A Practical Handbook. 2nd ed. Springer Nature; 2018:1-40.
• Virtual Transesophogeal Echocardiography. Standard views: 2D TEE model. University Health Network. Peter Munk Cardiac Center. 2015. http://pie.med.utoronto.ca/tee/TEE_content/TEE_standardViews_intro.html