Enter the E/A ratio, peak early diastolic velocity (E), and peak late diastolic velocity (A) into the calculator to determine the missing variable.

E/A Ratio Calculator

E/A Calculation
E/A Interpretation

Enter any 2 values to calculate the missing variable.

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E/A Ratio Formula

The following formula is used to calculate the E/A ratio for a given peak early diastolic velocity (E) and peak late diastolic velocity (A).

EA = E / A

Formula source:  Nagueh SF, Smiseth OA, Appleton CP, et al. Recommendations for the evaluation of left ventricular diastolic function by echocardiography: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging (J Am Soc Echocardiogr. 2016;29[4]:277–314)

Variables:

  • EA is the E/A ratio
  • E is the peak early diastolic velocity
  • A is the peak late diastolic velocity

To calculate the E/A ratio, divide the peak early diastolic velocity (E) by the peak late diastolic velocity (A).

What is an E/A Ratio?

The E/A ratio is a measurement used in echocardiography to assess diastolic function of the heart. It is the ratio of the peak velocity of early (E) to late (A) ventricular filling. This ratio helps in evaluating how well the heart relaxes and fills with blood during diastole. A normal E/A ratio indicates good diastolic function, while deviations from the normal range can indicate various types of diastolic dysfunction, which may require further medical evaluation and intervention.

How to Calculate E/A Ratio?

The following steps outline how to calculate the E/A Ratio.

  1. First, measure the peak early diastolic velocity (E).
  2. Next, measure the peak late diastolic velocity (A).
  3. Finally, calculate the E/A ratio using the formula EA = E / A.
  4. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Peak Early Diastolic Velocity (E) = 0.8 m/s

Peak Late Diastolic Velocity (A) = 0.6 m/s