Estimating LV Ejection Fraction by Bi-Plane Simpson Method on Echocardiography

 

Watch above video showing LVEF estimation by Simpson method.

The Simpson method calculates left ventricular ejection fraction (LVEF) by tracing the endocardial border of the left ventricle in both apical four-chamber and two-chamber views. The volumes during diastole and systole are determined, and LVEF is calculated as the difference between these volumes divided by the end-diastolic volume. Steps to Calculate LVEF Using Simpson's Method

• Obtain Views:

  • Acquire apical four-chamber and two-chamber views of the heart.
  • Ensure optimal imaging quality to avoid foreshortening.

• Trace Endocardial Borders:

  • In both views, trace the endocardial border of the left ventricle during end-diastole (maximum volume) and end-systole (minimum volume).
  • Be careful to exclude structures like papillary muscles from the tracing.

• Calculate Volumes:

  • Use the traced areas to calculate the left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV).
  • The volumes can be computed using the formula:
    • LVEDV = Volume at end-diastole
    • LVESV = Volume at end-systole

• Apply the Ejection Fraction Formula:

  • Calculate the ejection fraction using the formula:
    • EF (%) = (LVEDV - LVESV) / LVEDV x 100

• Interpret Results:

  • A normal ejection fraction typically ranges from 55% to 69%.
  • Values below this range may indicate varying degrees of heart dysfunction.

Considerations and Limitations

• Operator Dependency:

  • The accuracy of the Simpson method is highly dependent on the operator's skill and the quality of the echocardiographic images.

• Image Quality:

  • Poor image quality can lead to inaccurate volume measurements, affecting the ejection fraction calculation.

• Arrhythmias and Wall Motion Abnormalities:

  • These conditions can complicate the assessment and may hinder accurate tracing of the endocardial borders.

By following these steps and considerations, the Simpson method can provide a reliable estimate of left ventricular ejection fraction in clinical practice.