Parasternal long axis view
From Echocardiography in ICU
To get the parasternal long axis view
The parasternal window is located next to the sternum, between the 3rd and 5th intercostal spaces. You may get better images one or two intercostal spaces lower, but you won't be in the true long axis of the left ventricle.
-The notch on the probe must be directed toward the sternum, at 9-10 o'clock.
-Place the probe against the left lateral border of the sternum, just at the sterno-costal angle.
-Start at the highest intercostal space where you can get a good image (3rd or 4th), go to the next lower intercostal space if you can't obtain a good image.
Criteria of quality for a good parasternal long axis view
-the septum must be as horizontal as possible
-you should not visualize the apex of the left ventricle
-you should see the aortic and mitral valves but not the tricuspid valve
What will you see on the parasternal long axis view?
RV: the right ventricle is on the top, closer to your probe. On this view you see the right ventricle outflow tract. You can look for a right ventricle dilatation (diameter > 2/3 of left ventricle diameter). You can also get an idea of the right ventricular contractility.
-LV: left ventricle: this view is the best for the measurement of the size and walls thickness of the left ventricle.
-MV: mitral valve: this is the best view to look at the structure of the mitral valve. You see the anterior leaflet on the top and the posterior leaflet on the bottom. You can put color Doppler to look for mitral regurgitation.
-Ao V: aortic valve: you should look at the opening of the aortic cusps. You may suspect aortic stenosis in the presence of calcifications of the cusps or restriction of the valve opening. With color Doppler you can look for aortic regurgitation
-IVS: interventricular septum and PW: posterior wall. You can assess their thickness and contractility
-Ao: aortic root. You can measure the aortic annulus, the dimensions of the sinus of Valsalva, and the dimensions of the aortic root. The aortic walls should be parallel.
-LA: left atrium. It should be the same diameter than the aortic root
-Desc Ao: descending aorta, which will help you to distinguish between a pericardial and a left pleural effusion
-pericardium: it is the most echoic structure, appears very bright. This is the best view to distinguish between pericardic and pleural effusions.
Color Doppler of mitral and aortic valves
By putting color Doppler on the mitral and aortic valves, you can detect valvular regurgitation.
Be careful, this is not a good view to quantitate a valve dysfunction since the Doppler beam is almost perpendicular to the flow.
For the same reason, the detection of a valve regurgitation will be based on the timing of the flow in the cardiac cycle, not on the color coding of the jet.
On this loop there is no aortic or mitral regurgitation. Please go to specific sections on mitral valve and aortic valve, or to the images library, to visualize examples of regurgitation from parasternal long axis view.
How to improve your image?
If you see the tricuspid valve --> angle your probe upwards (you are too high and your ultrasound beam is aiming too anterior)
If you see the apex of the left ventricle --> rotate your probe a few degrees clockwise (you are foreshortening the left ventricle)
If you lose the image --> come back closer to the sternum, you may be sliding on the chest (take anchor on your wrist but don't put too much pressure on the probe, you will slide)