TOE Views

Know the Probe

• Modified gastroscope.
• For patients weighing more than 25 kgs.
• Chemically sterilised.
• Use dental gaurd - protect teeth and probe.

Movements of the probe:

1. Advanced/withdrawn
2. Clockwise/Anticlockwise
3. Ante/Retroflexion
4. Flex to left/right
5. Rotation of transducer - forwards/backwards.

Rotation:

• 0 - Transverse image
• 90 - Longitudinal
• 180 - Mirror image.

Standard Sector display:

• Apex - top. Locates posterior cardiac structures.
• 0 - Letf of the image is patients right.
• 90 - Left is inferor. Right is Anterior. ? Why not superior??!

Adjustments before start:

1. 2-D gain: chambers black and tissues white.
2. Colour gain: Just below that which produces noise and speckling
3. Depth: 6 to 16 cms usually.

Axis:

1. Short axis: Perpendicular to the length of the structure of interest
2. Long axis: Parallel to the length. For LV it is any image plane in which both aortic and mitral valves can be seen simulatneously.

Image collection: At four levels

1. Upper Oesophageal
2. Mid oesophageal - a. Aortic; b.Ventricular.
3. Transgastric
4. Deep trans gastric

Mid oesophageal Aortic Views:

1. Five chamber view (0)
2. AV Short axis view (40)
3. AV Long axis view (130)
4. Ascending Aorta SAx view (40)
5. Ascending Aorta LAx view (130)
6. RV inflow-outflow view (80)
7. Bicaval View (110)

Mid oesophageal Ventricular Views:

1. Four chamber view (0 -20)
2. Commissural view (60)
3. Two chamber view (90)
4. Long axis view (130)

Trans gastric Views:

1. Basal Short axis view (0)
2. Mid SAx view (0)
3. Two chamber view (90)
4. RV inflow view (90)
5. Deep transgastric LAx (0)
6. Transgastric LAx (120).

MidOesophageal Aortic Views:

1. Five Chamber View (0) : 35 to 40 cms. Good starting point. Seen are RA, RV, LA, LV and LVOT.
2. AV SAx (40) : Withdraw slightly. Mercedes Benz Sign. NCC is adjacent to IAS. RCC is most anterior. Withdraw slightly to see the origin of the coronaries.
3. AV LAx (130): RCC is most anterior. It is adjacent to RVOT. The cusp seen adjacent to AML is NCC/LCC. Transverse pericardial sinus is seen between LA and posterior wall of the aorta. Oblique pericardial sinus is seen between oesophagus and LA.
4. Ascending Aortic SAx view(40): Seen are Proximal AA, MPA, RPA and the SVC. At lower level LA is most posterior. As probe is withdrawn RPA seperates oesophagus from aorta.
5. AA LAx view(130) : RPA seen in SAx. Both walls of ascending aorta can be examined.
6. RV inflow-outflow view(80) : Probe turned left to show pulmonary and tricuspid valves. RA, TV and RVOT appear to wrap around AV from left to right. Good for CW of TV flows. Posterior leaflet of TV is to the left and anterior to the right.
7. Mid oesophageal bicaval view(110): Turn probe to the right. SVC is seen to the right. IVC to the left. Eustachian valve is seen at the junction of IVC and RA. Thin central fossa ovalis is seen where PFO is sought.

Mid oesophageal Ventricular views:

Important to assess MV and LV.

LV is divided into 3 levels: Basal, Mid and Apical.

Basal and Mid levels have 6 segments: Anterior, Lateral, Septal, Inferior, Anteroseptal and Posterior.

Apical segment has only 4 segments: Anterior, Lateral, Septal and Inferior.

So there are totally 16 segments.

The mid segments are known as midpapillary. Apical segments are poorly visualised.

1. Mid oesophageal 4C View(0-20): Forward rotation is to avoid AV and maximise TV diameter. Retroflex to avoid foreshortening of the LV. To start image should be centered on LV and MV. Septal wall is seen on the left and lateral wall on the right. Anterolateral papillary muscle may be seen arising from the lateral wall. AML is seen on the left and PML on the right. Turn the probe to the right to see RV, TV and interatrial septum. Turn left and withdraw to see LUPV and descending thoracic aorta. Advancing beyond 4 C view or retroflexing brings coronary sinus long axis in view.
2. Mid oesophageal Commisural View(60): Specifically indicated for assessment of MV function. AML is seen between two scallops of PML. From left it is P1, A2, P3. Posteromedial papillary muscle is seen on the left and anterolateral is seen on the right.
3. Mid oesophageal 2 C view(90): Useful for MV and LV assessment. Coronary sinus is seen on the left and LAA is seen on the right of the image. AML is seen adjacent to LAA and PML is seen on the left of the image. Foresortening is present if LV lengthens with rotation. Another clue is excessive motion of the apparent apex. Posteromedial papillary muscle is seen to arise from the inferior wall. In this view inferior wall and anterior wall are seen.
4. Mid oesophageal LAx view(130): LVOT and MV are visualised simultaneously. No papillary muscle should be seen. The cavity on the far right of the screen is RVOT. The image cuts the midsection of the MV perpendicular to the intercommisural line. Useful to assess MV, AV and LV function. Posterior and anteroseptal walls are seen. Apical segments are often not seen.

Pulmonary veins:

4 Veins: LUPV, LLPV, RUPV and RLPV.

Upper better and easily seen. Suitable for doppler nterrogation.

1. LUPV: Easiest. Just lateral to LAA. From 5C view, turn probe slightly to left. Rotate forward 15 degrees (in some up 90). Runs anteroposterior. So suitable for doppler.
2. LLPV: Enters LA just below LUPV. Runs lateral to medial. Best seen by slightly advancing from LUPV view. Comes into view as LAA disappears.
3. RUPV: Runs ateroposterior. Lies adjacent to SVC. From 5C view, turn the probe to the right, RUPV is seen as it curves over the SVC. But better seen in the longitudinal image plane. From bicaval view turn the probe to the right or rotate the transducer by another 10 - 20 degrees. RUPV is seen as SVC disappears from the view.
4. RLPV: slightly advance from RUPV view in the transverse image plane. Difficult to doppler.

Tip: Use colour doppler to visualise flow to locate pulmonary veins. Low velocity flow is directed towards the probe.

My System:

1. Start with trans-gastric views.

0

90

120

Aims:

• Assess ventricular function (0 and 90)
• Assess ventricular thickness (0 and 90)
• Assess mitral valve - also with colour (0 and 120)
• Assess aortic valve - CW and PW doppler (0 or 120) - Colour if AS/AR
• Assess LVOT - PW

2. Obtain four chamber view.

3. Obtain mitral views - 60, 90 and 130.

4. Obtain mitral doppler.

5. Aortic short axis view.

6. Aortic Long axis view

7.

My image stores include:

1. Trans gastric short axis LV
2. Transgastric LV M-mode
3. Transgastric long axis LV
4. Transgastric LV M-mode
5. Transgastric 120 Aorta+LVOT -colour compare
6. Transgastric 120 Aorta + LVOT CW
7. Transgastric 120 LVOT PW
8. Transgastric 120 Aortic valve PW
9. Midoesophageal 4 chamber view
10. LVOT long axis
11. LVOT long axis colour
12. Mitral valve PW
13. Aorta SAx
14. Mitral Valve commisural view 60
15. Mitral valve 90
16. Mitral valve 130
17. RV Inflow - Outflow 80
18. Tricuspid regurgitation colour
19. Tricuspid regurgitation + inflow CW
20. SVC - IVC view
21. PFO - Colour
22. RUPV colour + PW
23. LAA
24. LUPV PW
25. Pulmonary CW
26. Descending aorta
27. Arch of the aorta