2. Advantages of TEE
- The advantage of TEE over TTE is usually clearer images,
especially of structures that are difficult to view transthoracically
(through the chest wall).
- the heart rests directly upon the esophagus leaving only
millimeters that the ultrasound beam has to travel. This reduces
the attenuation (weakening) of the ultrasound signal,
generating a stronger return signal, ultimately enhancing image
and Doppler quality.
3. Advantages of TEE
- Comparatively, transthoracic ultrasound must first traverse skin, fat, ribs and
lungs before reflecting off the heart and back to the probe before an image
can be created. All these structures, along with the increased distance the
beam must travel, weaken the ultrasound signal thus degrading the image
and Doppler quality.
- In adults, several structures can be evaluated and imaged better with the
TEE, including the aorta, pulmonary artery, valves of the heart, both atria,
atrial septum, left atrial appendage, and coronary arteries. TEE has a very
high sensitivity for locating a blood clot inside the left atrium.
6. Probe preparation and placement
⢠Minimally invasive and complications are rare
provided care is taken and contraindications
avoided.
⢠GE hemorrhage and esophageal perforations are
rare but potentially fatal.
⢠Probes are modified gastroscopes and suitable
for use in patients heavier than 25 kg.
⢠Small probes are available for pediatric use.
7. Probe Insertion Techniques in OT
⢠In the operating room, the patient remains supine and probe
is typically placed from the head of the bed with slight
anteflexion of the probe.
⢠The bite block should not be placed in the mouth before
placement of the probe, because this will displace the tongue
posteriorly and obstruct probe passage.
⢠Lifting the mandible anteriorly and caudally usually opens the
mouth and displaces the tongue anteriorly to allow smooth
probe placement.
⢠A laryngoscope can be used to facilitate probe placement into
the esophagus, or the fingers can guide the probe into the
posterior fossa in anesthetized patients.
⢠Ensure the patient is deeply anesthetized or paralyzed before
inserting fingers into the oropharynx, as the bite block is not
present
11. Probe position and orientation
⢠Apex of sector scan
marking origin from
esophageal probe is shown
at the top and locates post
structures.
⢠Transverse image plane at
00, L of image is towards
patientâs R
12. Probe position and orientation
⢠In the vertical plane
image 900, L side of
image is inferior and
points towards patientâs
feet.
⢠Right side of image is
anterior and points
towards patientâs head.
13. Area of interest in the center
⢠Once a structure has been centered within one
image plane, it will remain in the center in
subsequent image planes as the transducer is
rotated between 0-180.
⢠This feature helps in 3-dimentional assessment
of the structure.
⢠To center the structure in a image:
â At 00, turn shaft Left or Right
â At 900, advance or withdraw shaft vertically
14. Systematic Examination
Standard Views
⢠Connect ECG.
⢠Adjust 2D gain to get chambers black and tissue
grey/white.
⢠Adjust colour gain .
⢠Start at sector depth of 12 cm that is
standardised to assess heart size: small, normal
or dilated.
⢠Rule of thumb: At TG view at 12 cm, LV should
fill up 2/3rd of the sector.
15.
16.
17. Standard Views
⢠Long axis view particularly in relation to LV
means: both aortic and mitral valve must be
seen.
⢠Depths for various views:
â Upper esophageal (UE) :20-30cm
â Mid Esophageal (ME) :30-40cm
â Transgastric (TG) :40-45cm
â Deep Transgastric :45-50cm
⢠20 standard views
20. Starting Point of TEE Examination:
Beyond 20 viewsâŚâŚ.. The 5-Chamber View
⢠With sector scan at 00,
advance probe to 35-
40cm until AV is seen
oblique cross section
⢠5 chambers
â RA
â RV
â LA
â LV
â LVOT
⢠.
21. Mid-Esophageal 4-Chamber View
⢠From 5-chamber view, advance
probe until Aortic valve is lost.
⢠150 rotation to maximize tricuspid
annular view.
⢠Retroflexion to prevent
foreshortening of LV.
⢠For Viewing: LV, RV, Septum :
Atrial & ventricular
22. ME 4-Chamber View : What is more?
Coronary Sinus View
Advancing and turning
the probe right or
retroflexing probe,
slightly beyond 4-
chamber view brings
coronary sinus in long
axis as it runs along
posterior AV groove
behind mitral annulus.
23. ME commissural view (600)
⢠From 4-chamber view rotate transducer 600 until
commissures viewed. Indicated for assessment of
Mitral Valve function.
⢠A portion of ant. mitral leaflet appears to float in the
center of LV inflow tract between 2 scallops of post mitral
leaflet.(P1-A2-P3)
⢠Image plane cuts post leaflet twice, and should not be
confused with mitral cleft/ perforation.
⢠Papillary muscle: L Posteromedial; R Anterolateral
25. Mid Esophageal 2-Chamber View 900
(ME 2C)
⢠From commissural
view, rotate 900,
until 2 chamber
view is seen.
⢠Useful for
assessment of LV
and MV.
⢠Identified by
appearance of
coronary sinus on L
and LA appendage
on R
26. Mid Esophageal 2-Chamber View 900
(ME 2C)
⢠In contrast to 4-C view, PML now appears
on L and AML on R adjacent to atrial
appendage.
⢠Inf wall is seen on L and ant wall on the R.
⢠If the LV appears to lengthen during
rotation of the transducer, it indicates
apex was not adequately visualized in 4-C
view.
⢠Clue to LV foreshortening ď excessive
motion of apparent apex. When true apex
is visualized, wall motion and thickening
appear similar to surrounding myocardium
unless WMA present.
⢠Extension of apex below bottom of screen
in the 2-chamber view at 15cm depth
indicates LA/LV dilatation.
29. ME Long Axis View (1300)
ME AV LAX
⢠From AV short axis view,
transducer is rotated 90 deg-
130 deg to obtain long axis
view of AV. Probe is turned R
and L until leaflet excursion is
clear.
⢠RCC being most ant, is seen
lower most, adjacent to RVOT.
The cusp seen adjacent to AML
is either NCC(more often) or
LCC.
⢠If fluid has collected behind
heart, oblique pericardial sinus
may be seen between post wall
of LA and esophagus.
⢠Fluid in transverse pericardial
sinus is sometimes seen
between post wall of ascending
aorta and LA.
30. To Obtain the View ME AORTIC VALVE SHORT AXIS VIEW (45)
⢠Insert the probe to the ME, sector depth 8-l0cm.
. Find the ME 4C (0:) withdraw cephalad to obtain the ME 5C view (0:) that includes the LVOT and
AV.
. Rotate omniplane angle to 30- 45.
⢠Center aortic valve and aim to make 3 aortic valve cusps symmetric
⢠withdraw probe for coronary ostia . Advance probe for LVOT
31. ME RV inflow-outflow view (800)
⢠From ME 5-chamber view, rotate
transducer to 800 and turn
clockwise (R) to show TV and PV.
⢠Note RV free wall on L and RVOT
on the R.
⢠An in situ PAC can be seen to wrap
around AV from RA to TV to RVOT.
⢠This view provides good alignment
between a CW Doppler signal and
a jet of tricupid regurgitation.
⢠TV valve: Post leaflet on L
Ant leaflet on R
32. ME Ascending Aortic Short Axis View (400)
ME Aortic SAX
⢠From 5-chamber view, the
transducer is rotated between 00
to 400 and the probe is
withdrawn until short axis view
of ascending aorta is seen.
⢠The view shows proximal
ascending aorta, MPA, RPA and
SVC.
⢠Satisfactory alignment of Doppler
signal with blood flow through
MPA can be obtained.
⢠As the probe is progressively
withdrawn, MPA, initially seen as
circle becomes oval as it curves
posteriorly towards probe before
branching into R and L. At this
level, RPA separates probe from
aorta , and not LA.
33. ME Ascending Aortic Long Axis View (900-1300)
ME Aortic LAX
⢠From ascend aorta SAX
view, transducer is rotated
900 to 1300 to show ascen
aorta in short axis.
⢠Withdraw probe until RPA is
seen
⢠Both walls of ascen aorta
can be seen by withdrawal
of probe and minor
backward rotation.
⢠In many patients views can
be obscured by large
airways.
34. Descending Thoracic Aorta, Aortic Arch SAX
⢠The descending thoracic aorta and aortic arch are imaged in short and long axis
view with four standard views.
⢠Screen depth should be reduced to 6 cms.
⢠From ME 4-C view, the shaft of probe is turned to left (anticlockwise) until the
circular, SAX, cross section of the descending thoracic aorta is centered on the
screen.
35. ME Descending Thoracic Aorta LAX
In the Descending Aorta LAX
view (90°) the imaging plane is
directed thru the longitudinal
axis of the descending aorta.
The distal aorta is to the display
left and the proximal aorta to
the display right.
37. Upper Esophageal Arch Short Axis Arch SAX
⢠The transducer is then rotated 600-900 until
the distal arch is seen in short axis.
⢠In this view left subclavian artery can usually
be seen in upper right side of display.
⢠More proximal left common carotid and
brachiocephalic arteries can occasionally be
seen by turning the probe to the right
(clockwise) to open up the view of mid aortic
arch.
38. Transgastric (TG) Views
⢠TG probe position provides range of useful views for
assessment of MV, LV and RV.
⢠TG mid SAX view commonly used in assessment of LV
function and in conjunction with TG basal SAX, allows
visualization of 12 out of 16 LV segments.
⢠TG apical SAX view (not described by ASE/SCA) can
visualize remaining 4 apical segments.
⢠TG long axis and Deep TG LAX provide the only TEE
images for satisfactory alignment of Doppler for blood
flow through AV.
⢠ME and TG views may have some overlap but in practice
they are complementary.
39. TG Basal Short Axis View (00)
⢠From ME 4-C view, probe is advanced into stomach and anteflexed
until the characteristic âfish-mouth opening of MVâ is seen with all
mitral segments.
⢠Interpret IVS carefully, if cut is oblique or too high, the septum
may appear too thinned, and appear to move abnormally as a
result of scanning across LVOT.
40. TG Basal Short Axis View (00)
⢠Imaging plane is directed longitudinally thru the basal inferior wall of the LV with all 6
basal LV segments viewed at once from the stomach.
⢠This permits a view of the MV that is parallel to the annulus and posterior commissure
closest to the probe.
⢠Use this view to assess
Left Ventricle: size, function
Ventricular Septal Defect (VSD)
Mitral Valve: planimetery orifice area
41. TG Mid Short Axis View (00)
TG Mid SAX
⢠From basal short axis view, probe is advanced slightly, and then anteflexed to keep it apposed to the
diaphragmatic surface of stomach to develop TG mid-papillary short axis of LV.
⢠Gentle adjustment of flexion with forward rotation up to 150 may be helpful in avoiding oblique imaging
indicated by oval shaped LV.
⢠Posteromedial papillary muscle is seen at 1 oâclock position and anterolateral papillary muscle is seen at
5 oâclock.
⢠Probably most widely used view , useful for monitoring global LV function (fractional area change),
regional LV function (RWMA), and preload (end-diastolic area) .
⢠Best used by saving âloopsâ at different stages and then comparing later.
42. TG 2-Chamber view (900)
TG 2 C
⢠From mid short axis view,
the transducer is rotated to
900 to develop TG 2 Chamber
view.
⢠View to evaluate ant
(bottom of screen) and inf
(top of screen) of LV at the
basal and mid level.
⢠Apical segments usually not
seen.
⢠Best view for mitral sub-
valvular apparatus.
44. TG Long Axis View (1200)
TG LAX
⢠An alternative view
suitable for Doppler
evaluation of AV and
outflow tract.
⢠From Mid SAX, is rotated
to 120 deg until LVOT is
seen at the bottom of the
screen.
⢠Deep TG LAX and TG LAX
are often difficult to
obtain.
45. TG Long Axis View (1200)
TG LAX
In the TG LAX view (110-120°) the imaging plane is
directed longitudinally thru the LV to image the aortic
root in LAX. The LVOT and AV appear on the display
right, depending on the depth settings. This is view is
similar to the ME AV LAX view and permits better
spectral Doppler alignment.
46. TG Mid RV View
⢠By turning the probe right (clockwise),
the image may be centered on the RV
SAX.
⢠Crescentic shape and more extensive
trabeculae of RV compared to LV are
evident. RV wall thickness is normally
half that of LV.
⢠RV free wall has no formal segmental
classification but terms like basal, apical,
anterior and inferior are used.
⢠RV usually not cut in true short axis, this
combined with asymmetric RV shape,
makes assessment of chamber size and
thickness potentially unreliable.
47. TG RV Inflow View (900-1200)
TG RV Inflow
⢠From TG 2-chamber view, the shaft
of the probe is turned to right
(clockwise) to obtain RV inflow
view.
⢠Appearance of RV in this view is
distinguished from LV by its
diamond shape and thinner walls.
⢠Can be difficult to obtain, alternate
strategy is to start from mid short
axis view, center on RV and rotate
transducer 900.
⢠This view shows RV on left and RA
on right of the screen, and is useful
for assessment of tricuspid
subvalvular apparatus.
48. Deep TG Long Axis (00) View
Deep TG LAX
⢠From TG Mid SAX view,
probe is advanced into
stomach and then slowly
withdrawn keeping it
anteflexed, until it contacts
stomach wall.
⢠Image is similar to an upside
down ME 5-C view.
⢠Ideal image for estimation of
velocity through AV and
LVOT.
49. Deep TG Long Axis (00) View
Deep TG LAX
Use this View to
â Diagnose paravalvular leak prosthetic aortic valve
â AV gradient spectral doppler
â LVOT gradient spectral doppler