Apical 4 & 5

The apical 4 chamber and apical 5 (AP 4, AP 5) chamber views are high-yield images for measurements. The AP 4 is obtained first, then the transducer head is angled slightly up to open the left ventricular outflow tract (LVOT) which is referred to as the 5th chamber.

Transducer Placement (Figure 1)

Start lateral to the mid-clavicular line at the 4th-5th intercostal space and move medially (aim for the patient’s point of maximal impulse)
May be more medial and lower in intubated patients
Pendulous breast tissue, elevate the tissue and place the transducer under the breast fold
The indicator points to the patient’s left mid-axillary line (3 o’clock position, or down towards the bed)
From the AP 4 angle the face of the transducer opening up the left ventricular outflow tract (LVOT) to obtain the AP 5

Image Orientation (Figures 2 and 3, Video 1)

Apical 4 chamber

The right ventricle (RV), left ventricle (LV), left atria (LA), right atria (RA), mitral valve, tricuspid valve are well visualized

Apical 5 chamber

The LVOT is well visualized, the RV and LV can also be seen. The RA and LA are harder to see in this window

Measurements of diastolic function are obtained in the AP 4 and measurements of stroke volume and cardiac output are obtained from the AP 5

Figures and Clips

Figure 1 - Transducer Placement

Figure 2 - Apical 4 and 5 Windows

Figure 3 - Apical 4 and 5 Windows

Figure 4 - Ideal A4C

Figure 5 - Ideal A5C

Figure 6 - Ideal A5C with color flow Doppler through the LVOT

Clip 1 - A4C with Cardiac Preset

Clip 1 - A5C with Cardiac Preset

References

Moore, Christopher L., and Joshua A. Copel. “Point-of-care ultrasonography.” New England Journal of Medicine 364.8 (2011): 749-757.