Study initiation
We begin the TEE examination in the mid-esophagus with the TEE imaging plane at 0° and a four-chamber view, demonstrating the basal and mid segments of the inferoseptum and anterolateral LV walls (Figure 1). This view demonstrates the septal leaflet of the tricuspid valve, and if the probe is retroflexed, the posterior leaflet of the tricuspid valve. Color Doppler and continuous wave (CW) Doppler are applied to assess for regurgitation. If color Doppler suggests an appropriate orientation of the TR jet, CW Doppler is acquired to quantify the RV systolic pressure. With the probe retroflexed and with the probe slightly advanced to exclude the left ventricular outflow tract (LVOT), the A2 scallop and the P2 scallop of the mitral valve are visualized (Figure 2). Flexing and/or withdrawing the probe demonstrate the LVOT as well as the A1 and P1 scallops of the mitral valve. Retroflexing and/or advancing the probe demonstrate a foreshortened ventricle as well as the A3 and P3 scallops [13]. Color Doppler is applied to assess for valvular regurgitation. By advancing the probe and turning the probe clockwise, the right atrium (RA), tricuspid valve (TV), and right ventricle (RV) are visualized (Figure 3). Next, the probe is withdrawn slightly and rotated clockwise to visualize the interatrial septum. Color Doppler is applied to assess for an atrial septal defect (Figure 4). The TEE probe is then rotated counterclockwise and anteflexed in order to demonstrate the LVOT and aortic valve. Color Doppler is applied to assess for aortic regurgitation (Figure 5). Finally, the probe is turned counterclockwise, and anteflexed to visualize the left atrial appendage (LAA) and the left upper pulmonary vein (LUPV) (Figure 6). Pulsed wave Doppler are performed with the sample volume at the mouth of the LAA and LUPV.
Imaging Plane Advancement 0 – 165 Degrees
A comprehensive, multiplane assessment with a specific cardiac structure as a primary focal point is then performed, based on the indication for the TEE. For example, if the TEE is being performed on a patient in atrial fibrillation to exclude the presence of a LA/LAA thrombus, the LAA is chosen for this next interrogation. In a patient with mitral valve prolapse and suspicion of endocarditis, the mitral valve is chosen and will be presented here in more detail. The probe is turned to bring the patient specific structure of interest into the center of the screen at 0°. Then, the imaging plane is increased in 15–20° increments from 0° to 165°. After each change in imaging plane, 2D and color Doppler images are recorded. If a valve or the interatrial septum is the anatomic structure of choice, color Doppler is applied after each transducer angle change to assess for regurgitation or interatrial flow, respectively. If the interatrial septum has been selected as the anatomy of specific interest, attention is made to the optimal imaging plane for subsequent saline contrast injection. Selected sequential images for a TEE examination of a patient with suspected mitral valve endocarditis is provided in Figure 7.
135° Imaging plane
After completing data acquisition at a 165° imaging plane, the imaging plane is decreased to 135°. The aortic valve then becomes the focus for orientation of all subsequent views. The probe is turned to demonstrate the left ventricle long-axis view (Figure 8) with the basal and mid segments of the inferolateral wall and anteroseptum. The right coronary cusp and either the left or non-coronary cusp of the aortic valve as well as the P2 and A2 scallops of the mitral valve are also seen. The aortic and mitral valves are assessed with color Doppler. The probe can be withdrawn slightly to assess the ascending aorta for atherosclerotic plaque and proximal dissection.
Maintaining the imaging angle at 135°, the probe is turned clockwise to demonstrate the right and left atria and interatrial septum (Figure 9). The interatrial septum appears horizontally across the screen, and the fossa ovalis is well visualized. Color Doppler is applied to identify atrial septal defects. This view is helpful for assessing tricuspid valve pathology, the coronary sinus, and pacing wires/right heart catheters. Additionally, the right atrial appendage (RAA) is visualized and pulse wave Doppler is applied to assess emptying velocities. Agitated saline injections for patent foramen ovale detection may be performed at this or other orientations (see later).
Maintaining the imaging plane at 135°, further clockwise turning of the probe allows for visualization of the superior vena cava and right upper pulmonary vein (Figure 10). Color Doppler and pulse Doppler of the pulmonary vein are acquired.
90° Imaging plane
Maintaining the imaging plane at 135°, the probe is then turned counterclockwise to view the aortic valve. The imaging plane is then decreased to 90° for a 2D and color Doppler assessment of the long axis of the left ventricle, the aortic valve and ascending aorta (Figure 11). Slight clockwise turning will demonstrate the right ventricular outflow tract (RVOT) and pulmonic valve (Figure 12). Further clockwise turning will demonstrate the tricuspid valve (Figure 13) where color Doppler is applied as well as CW Doppler (if aligned with flow). Further clockwise turning will demonstrate the bicaval view (Figure 14). In the bicaval view, the interatrial septum traverses horizontally across the screen, and an atrial septal defect can be appreciated with color Doppler. We typically choose this view for agitated saline injection (rest, post-Valsalva, and cough) for a suspected patent foramen ovale, but the previously described 0° (Figure 4) and 135° orientations (Figure 9) or the subsequent 60° orientation (see later) may also be used. The RA and RAA are visualized. Pulse wave Doppler of the RAA is performed to assess emptying velocities.
Further clockwise turning of the probe identifies the right upper pulmonary vein (Figure 15). Slight probe advancement and additional clockwise rotation can demonstrate the right lower pulmonary vein. Each pulmonary vein is assessed with color and pulse wave Doppler.
While maintaining the imaging plane at 90°, the image depth is increased and the TEE probe is turned counterclockwise to obtain the two-chamber view, including the LA, the LV, and the mitral valve (Figure 16). The probe is then withdrawn slightly, anteflexed, and turned more counterclockwise to visualize the LAA at 90° (Figure 17). Pulse wave Doppler is applied to assess emptying velocities. Further counterclockwise turning of the probe brings into view the left upper pulmonary vein and subsequently the left lower pulmonary vein (Figure 18). Each pulmonary vein is assessed with color Doppler and pulse wave Doppler.
40 – 60° Imaging plane
Maintaining the imaging plane at 90°, the probe is then turned clockwise to view the aortic valve. The image plane is then decreased to 50° – 60°, to obtain the short axis view of the aortic valve (Figure 19). The probe is advanced and withdrawn in this position to assess the anatomy directly below (LVOT) and above the aortic valve. Color Doppler is applied at the aortic valve and LVOT levels to assess for regurgitation. The anterior and posterior leaflets of the tricuspid valve are assessed with and without color Doppler. The right and anterior cusps of the pulmonic valve and main pulmonary artery are also seen in this view [14]. Color Doppler is applied to the pulmonic valve to assess for regurgitation. Clockwise turning of the TEE probe will demonstrate the interatrial septum again. Applications of color Doppler or agitated saline injections can be used to search for an atrial septal defect or patent foramen ovale (Figure 20).
Imaging plane 0° – Passing Through the Gastroesophageal Junction
The imaging plane is then decreased to 0° and the mitral valve, LAA, and interatrial septum can be reassessed if further data are desired. Subsequently, the probe is passively advanced through the gastro-esophageal junction as the TEE handle is turned counterclockwise to visualize the coronary sinus (Figure 21).
Transgastric Views
With the imaging plane at 0°, the TEE probe is advanced beyond the gastro-esophageal junction into the stomach to a distance of ~45 cm from the incisors. Once in the stomach, the probe is anteflexed to visualize the short axis of the ventricles (Figure 22). The distance that the TEE probe is advanced determines whether the short axis image is obtained at the level of the mitral valve, mid-ventricle, or apex. With the short axis of the LV centered in the screen, the imaging plane is increased to 90° and the control handle is turned slightly counterclockwise. This provides a 2-chamber view of the left ventricle (Figure 23). The imaging plane is then increased to 120° and the probe is turned clockwise and flexed to demonstrate the left ventricular outflow tract and aortic valve (Figure 24). Color Doppler can be applied to assess for aortic regurgitation and continuous wave (CW) Doppler may be applied to measure the aortic valve gradient. Finally, while maintaining the imaging plane at 120°, the probe is turned clockwise to visualize the right ventricle, right atrium, tricuspid valve, and RVOT with and without color Doppler (Figure 25).
Thoracic Aorta and Pulmonary Artery
The imaging plane is decreased to 0° and the probe is rotated counterclockwise to demonstrate the thoracic aorta in cross section (Figure 26). The probe is advanced until the aorta is no longer visualized (approximately 44 – 50 cm from the patient's incisors) and is then slowly withdrawn as the aorta is inspected for evidence of atherosclerotic plaque and dissection. To further survey plaque and other vessel wall changes, the imaging plane can be increased to 90° to visualize the long axis of the aorta. As the probe is withdrawn to the upper esophagus, the aortic arch is inspected (Figure 27). The probe is turned counterclockwise and withdrawn further to better visualize the distal ascending aorta. At the level of the arch, the imaging plane is increased to 90°. The pulmonic valve and main pulmonary artery are visualized (Figure 28). Color Doppler and CW Doppler across the pulmonic valve can be applied. The probe is then left in the neutral position and withdrawn from the patient.
Saline Contrast
Agitated saline contrast is often performed during TEE in patients with suspected paradoxical embolism due to a patent foramen ovale [15]. For these patients, we usually interrogate the interatrial septum from 0–180° to identify the best orientation to visualize the thinnest portion of the interatrial septum/fossa ovalis. The 90° orientation is often best, but this can vary. Saline is administered at rest, followed by injections with cough and post-Valsalva release. Except for cases of suspected persistence of a left sided superior vena cava, our preference is to inject agitated saline from the right arm so as to avoid potential obstruction to venous flow related to the patient's left lateral decubitus position.
