Parasternal long axis (PLAX/PSLA)

In the PLAX view, the RV appears as a triangular/elongated structure anterior to the LV. Only a small portion of the RV is visible, limiting assessment of overall RV size and function.

This view provides a qualitative glimpse of RV function and size but should be interpreted alongside other views for a complete RV strain assessment

 

What is Normal?

> Triangular shape 

> Smaller than the LV and should not violate the 1/3 rule with the RV, LVOT, and LA all being about 1/3 of the screen and being approximately the same size. 

> The RV should squeeze inward uniformly, with the free wall moving toward the septum during systole.

 

Figure 4: PLAX view with normal RV function 

 

 

What is NOT Normal?

> Visually reduced contraction  

> Visually, if the RV is equal to or larger than the LV, then there is likely RV dilation. In severely dilated RVs, the LV will appear to look compressed by the RV  

 

Figure 5: PLAX Cardiology convention demonstrating a prominent, dilated RV in the near field. 

 

Figure 6: PLAX cardiology convention demonstrating RV dilation and flattened septum. Note that the LV appears as if it is being compressed by the RV.