E-Point Septal Separation

Obtain a PLAX view with visualization of the mitral valve leaflets and interventricular septum.

Select M-mode and place the cursor at the tip of the anterior mitral valve leaflet.

Measure the distance from the interventricular septum to the point of maximal excursion of the anterior mitral valve leaflet (E-wave) on the m-mode tracing.

Interpretation

Normal: <7mm

Mild/Moderate LV Dysfunction (EF 30- 50%): 7-13mm

Severe LV dysfunction (EF <30%): >13mm

Tips

The more horizontal the ventricles lie in PLAX the more accurate the measurement.

Place the M-mode cursor as close to the tip of the mitral valve leaflet as possible.

Pitfalls

Measurement not accurate in patients who have pathology of the mitral valve or moderate to severe aortic regurgitation.

Patients with severely thickened interventricular septum such as in LVH or HOCM can have an overestimation of LV function.

Figure 1 - EPSS with normal LV function

Figure 2 - EPSS with low LV EF

Clip 1 - EPSS Cursor Placement

Prada, Gabriel, et al. “Echocardiographic applications of M-mode ultrasonography in anesthesiology and critical care.” Journal of cardiothoracic and vascular anesthesia 33.6 (2019): 1559-1583.

McKaigney, Conor J., et al. “E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction.” The American journal of emergency medicine 32.6 (2014): 493-497.