Cardiac: Parasternal Short Axis

1. 1

   From PLAX, rotate probe 90° clockwise (marker now pointing to left shoulder) to obtain PSAX.

2. 2

   Sweep superiorly for aortic valve level (Mercedes-Benz sign), then inferiorly to mitral valve level (fish mouth).

3. 3

   Continue to papillary muscle level — this is the standard level for wall motion assessment.

4. 4

   The LV should appear as a perfect donut. If it looks elliptical, adjust probe rotation.

5. 5

   Assess all 6 segments at papillary level for symmetric contraction.

6. 6

   Look for D-sign: flattening of the interventricular septum in systole = RV pressure overload.

7. 7

   Sweep to apical level — the LV should taper to a point with no papillary muscles visible.

• PSAX — Mitral valve level
• PSAX — Papillary muscle level
• PSAX — Apical level

• Regional wall motion abnormality
• D-sign (RV strain)
• LV geometry (donut shape)

• True short axis requires circular LV — if elliptical, adjust rotation

From PLAX, rotate probe 90° clockwise. Mitral valve level shows 'fish mouth' appearance.