Assessment of LV Function

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EPSS uses M-mode to measure the distance between the anterior mitral valve leaflet and the interventricular septum in early diastole. 

Steps:

1. Obtain a PLAX view.

2. Place the M-Mode cursor over the tip of the anterior mitral valve leaflet.

3. Acquire several cardiac cycles, freeze the image, and use calipers to measure the minimal distance between the anterior mitral leaflet and the septum.

Interpretation: It may be unreliable in conditions affecting mitral valve mobility (e.g., MS, MVR).

• Smaller EPSS = better LV function. 
• EPSS > 8 mm suggests reduced LVEF

FS uses M-mode to measure the percentage change in LV diameter between LV end diastolic diameter (LVEDD) and LV end systolic diameter (LVESD)

Steps:

1. Obtain a PLAX view

2. Place the M-mode cursor in the middle of the LV, avoiding the papillary muscles or the mitral valve

3. Freeze the image, and use calipers to measure LVEDD and LVESD. 

4. The machine calculates EF using these values

Interpretation: Dependent on PSL view; off-axis imaging can lead to under or overestimation. Regional wall motion abnormalities can also effect the calc.

FAC measures the percentage change in LV area between LV end diastolic area (LVEDA) and LV end systolic area (LVESA). 

FAC (%) = (LVEDA-LVESA)/LVEDA x 100

Steps:

1. Obtain a PSAX view at the level of the papillary muscles.

2. Measure LV area at end-diastole to obtain the LVEDA (max area)

3. Measure LV area at end-systole to obtain the LVESA (min area)

4. Apply the values into the equation above to obtain the FAC 

Interpretation: FAC requires correlation with LVEF

• The normal range is ~35-65%.
• Lower values suggest reduced LV systolic function

This estimates LVEF by tracing the LV endocardial border in both A4C and A2C views during systole and diastole. It is considered the gold standard because it actually measures the LV volumes. The term biplane refers to using both A4C and A2C planes rather than relying on a single imaging plane.

Steps:

1. Obtain clear A4C and A2C views

2. Freeze the image and trace the LV border at end-disatole to obtain LV EDV

3. Freeze and trace again at end-systole to obtain LV ESV

3. The machine calculates EF using the EF equation
 

Interpretation: This method requires high-quality images and is both time-consuming and highly operator-dependent.