The apical long axis (ALAX) can be a difficult view to master for many sonographers. A quality, on-axis image is obtained when the image transects the true apex and also needs to pass through the center of the mitral valve (commonly the middle scallops: P2 and A2). The aortic valve leaflets should also be seen to be opening well and the ascending aorta is opened out. It can sometimes be challenging to achieve all these aspects in the one image. Here are some tips for imaging this view on-axis every time!
The ALAX view is one of my favorite views.
So, where do we go wrong??
The #1 mistake made is over-rotation of the transducer. Sonographers often find that to visualize the aortic valve, they need to tilt the transducer anteriorly. This shuts down the MV and foreshortens the image. Usually when they tilt back to open out the LV/MV, part of the tricuspid valve is on view also. This is typical of an over-rotated image. Essentially the sonographer has rotated too far anti-clockwise and have obtained a “reverse A4C” view.
If you need to tilt anteriorly to see the AoV, you are over-rotated!!!
The image is usually salvaged very simply… Remember the golden rule of obtaining an on-axis image…. Tilt for the center, rotate for the sides (always in that order).
Firstly tilt the transducer to open out the LV/MV. Don’t be concerned with the aortic valve at this stage. Just focus on tilting the transducer to optimize the ventricle. If the tilt is correct, the apex will be fixed (not foreshortened) and you will be passing through the center of the mitral valve.
Now “rotate for the sides”. Hold the image still…. Then rotate clockwise slowly until the aortic valve opens out (don’t’ tilt anteriorly to achieve this or you will drift off axis again). The index marker should be facing towards the patients right ear, but this is just a guide – use the echo image to give you an indication of how much rotation is needed. If you drift off-axis, go back to tilt for the center and optimize the LV. You will know when you have rotated correctly when the aortic valve is seen to be opening.
This view will become second nature in no time, and if you follow the steps of the Golden Rule, you will never struggle again!
Image courtesy of Master Isolated Images at FreeDigitalPhotos.net