4 chamber view
From Echocardiography in ICU
How to get the apical 4 chamber view?Place your probe at the apex of the LV, located at the apical impulse. The probe is oriented toward the right shoulder, the notch at 2 or 3 o'clock.
The four chambers of the heart (left ventricle, left atrium, right ventricle and right atrium) must be visualized, as well as the atrio-ventricular valves: mitral and tricuspid valves. The intersection between the four chambers should draw a cross with the vertical lign represented by the inter-ventricular and inter-atrial septa. The horizontal line is created by the alignement of the tricuspid and mitral valve.
Remember to abduct the patient's left arm to widen the intercostal spaces and improve your echographic window.
What will you see?
The right chambers are on the left of the screen:
-RV: right ventricle. In apical 4 chamber view, the RV should not be larger than 2/3 of the LV width. You can estimate the RV function by looking at the vertical motion of the lateral tricuspid annulus. The contraction of the RV is mainly longitudinal.
-RA: right atrium.-TV: tricuspid valve. Should be a few millimeters more apical than the mitral valve. You can assess a tricuspid regurgitation with color Doppler. In this view you will have a good alignement of the Doppler beam with the regurgitant jet, which will allow you to estimate the right ventricle systolic pressure.
-LV: left ventricle. You can assess the overall function of the left ventricle and the contractility of the inter-ventricular septum, apex and lateral wall.
-LA: left atrium. In this view you can measure the long and short axis of LA and its area and volume. Most of the time you can see the merging of the pulmonary veins in the LA.
-MV: mitral valve. The anterior leaflet is close to the inter-atrial septum, the posterior leaflet is lateral. Apical 4 chamber is a good view to assess the direction of a regurgitant jet and to quantitate mitral stenosis (with CW Doppler).
Color Doppler in Apical 4 chamber
In this apical 4 chamber view, the color Doppler sector is located on the mitral valve to detect a mitral regurgitation. Mitral regurgitation will appear as a systolic blue (going away from the probe) jet going from the LV to the LA. There is no regurgitation in this example.
In this apical 4 chamber view, the color Doppler sector is located on the tricuspid valve to detect a tricuspid regurgitation. Tricuspid regurgitation will appear as a systolic blue jet from the RV to the RA. There is trace tricuspid regurgitation in this example, which may allow the calculation of right ventricle systolic pressure with continuous Doppler study.
Criteria of quality of the image
-The apex of the left ventricle should be close to the probe, and the lines of the crux should be vertical and horizontal, the intersection point at the middle of the image.
-You should visualize the mitral and tricuspid valves full opening and closing, and the atria.
-Be careful not to shorten the apex of the left ventricle, which would appear round-shaped and hyperkinetic.
-If the crux of the heart is tilted toward the right of the screen, you are too medial, you should translate your probe laterally.
-If the crux of the heart is tilted toward the left of the screen, you are too lateral (less frequent), you should translate your probe medially
-If you don't see the mitral and tricuspid valve of the atria, your probe is aimed too deep. You should angle the probe up to visualize the atria.
-If you don't see the LV apex or if the apex is fore-shortened, you are not at the apical window. You should try to scan one or two intercostal spaces lower.
-If you see a big and round-shaped right ventricle, you are probably too medial and too high. However at this location it will be easier to look and to align your beam on a tricuspid regurgitation.