Apical 4 Chamber view
The apical 4 chamber view is obtained by placing the transducer near the point of maximal impulse with the probe indicator at 3 o'clock (arrow). Other apical views will require rotation and tilting.
The probe slices through the apex, and right and left ventricles in this view. The atria are in the far field. The field cut of view is such that the aortic root and aortic valve are not seen in this plane.
RV - right ventricle, LV - left ventricle, DA - descending aorta, TV - tricuspid valve, MV - mitral valve, RA - right atrium, LA - left atrium
An ideal 4 chamber view looks like this
In the appropriate orientation, the septum lines up vertically near the center of the screen. The LV and LV apex should be vertically oriented and the LV should be parabolic in shape as shown. If the LV apex appears round or is off center you are likely "off axis" which can affect interpretation. This view is also used to assess RV size and function, atrial size, abnormal intra-atrial and interventricular septal movement, as well as diastolic function. A few institutions have standardized this view in right-left reverse with the left ventricle on the left side of the screen and the right ventricle on the right of the screen. The majority of hospitals otherwise use the convention we show above. LV - left ventricle, RV - right ventricle, LA - left atrium, RA - right atrium, TV - tricuspid valve, and MV - mitral valve.
Zoom in on the Left Ventricle
It is important attempt to get a good look at all of the walls of the left ventricle. In this view the inferoseptum, lateral wall and apex can be seen. The lateral wall is usually the least well seen here because the wall itself is parallel with the ultrasound beam.
In addition to LV function assessment, below are some examples of what additional information can be gathered in this view. In the apical 4 chamber view it is important to use color Doppler to assess the mitral valve, the tricuspid valve and the pulmonary veins. Spectral Doppler should also be used to assess for the filling pattern of both valve, and to help quantify regurgitation as well as diastolic function. Tissue Doppler is frequently used at the lateral and septal mitral annulus to help assess diastolic function as well. This is discussed further in the diastolic function section.
Assessment of mitral and tricupid valves
Use of color Doppler below shows the presence of tricuspid valve (left) and mitral valve (right) regurgitation. Quantification of mitral regurgitation requires use of spectral Doppler and is discussed elsewhere.
Assessment of diastolic function
This involves a combination of assessment of mitral valve inflow, pulmonary vein flow and tissue Doppler Normal examples are shown below. Diastolic function is covered in more detail in another section.
The E wave represents early passing filling and the a wave represents atrial contraction. Under normal circumstances the E wave is larger than the a wave and the deceleration time is not markedly prolonged or shortened.
Normal tissue Doppler of the septal (left) and lateral (right) mitral annulus. The E' and A' waves res present the same parts of the cardiac cycle as above, but the ' denotes that we are talking about tissue velocity movements and not blood flow. Note that the velocity of tissue is much lower than blood. The peak E' velocity if about 15cm/s, whereas the peak E wave velocity using PW Doppler above was about 80 cm/sec. Normally the peak E' velocities are 10 cm/s and 15 cm/s at the septal and lateral mitral annulus, respectively. This pictures above therefore show normal tissue Doppler velocities.
Pulmonary Vein Flow
Normal pulmonary vein flow pattern is assessed using a PW Doppler in the right upper pulmonary vein. The PW waveform has 3 components, an S wave that represents systole, a D wave that represents diastole and an A wave that represents reversal of flow during atrial contraction. Normally the S wave is larger than the D. Other nuances of pulmonary vein flow are covered elsewhere.
Right Ventricular Measurements
Tricuspid annular planar systolic excursion or TAPSE measurement to assess RV function. One can obtain an RV focused view making sure that base and apex are well seen. An M mode cursor is placed through the TV lateral wall annulus to capture the motion of base to apex of this area. The distance of excursion in systole (how much the annulus moves toward the probe) is measured. Additional measures of RV function, such as the fractional area change, can also be calculated from the four chamber view, if desired.