Parasternal short axis view
From Echocardiography in ICU
The parasternal short axis (PSS) represents a cross-sectional "slice" of the heart. You can swipe the ultrasound beam along the whole heart, from the basis to the apex, to analyze the different sections.
How do you get the parasternal short axis?
-Start from a good PSL. Indeed, to get the PSL, you have the landmarks of the ribs and sternum, it is easier to adjust the location, direction and orientation of the probe. You don't have these landmarks for the PSS: the location, rotation, orientation of the beam are variable.
-Turn your probe 90° clockwise when you have a good PSL, without changing the location and orientation of the probe. The notch on the probe should be at 1 o'clock.
If you put too much pressure on the probe, it will slide on the chest. It will be easier if you focus on one structure (aortic valve for example) and keep this element in the center of the screen.
PSS is often a difficult view to obtain in critically ill patients. If the PSL window was very low with a vertical septum, it will be very difficult to get a true PSS, it will probably more look like an off-axis apical view. You should try to scan one or two intercostal spaces higher. If there is no higher parasternal echographic window, just go to the apical or subcostal windows.
Criteria of quality for PSS
-the left ventricle should be round shaped and symetric
-the left ventricle should be in the middle of the screen
Remember that PSS is not a good view to look at the left ventricle apex, your probe is very far from it!
PSS, levels of imaging
To scan toward the basis of the heart you will direct your probe toward the right shoulder of the patient. To scan toward the apex, you will direct your probe toward the patient's left flank.