There are multiple ways to calculate the ejection fraction (EF), stroke volume (SV) cardiac output (CO) and cardiac index (CI). By default, encaptureMD uses volumetric data. We can adjust some of the values to calculate with different methods if required. Please review the information below and if you wish to change, contact [email protected].
It is up to the customer to choose the best method to acquire volume images. Using Teiccholz may result in inaccurate SV/CO and CI values. Simpson's rule may be a better option or using doppler-derived values, such as
SV = 3.14 * (LVOT diameter/2)^2 * LVOT VTI.
However, there are inaccuracies with this method based on its dependence on LVOT measurements.
Another option is to just take what the US machine delivers for these values. However, re-calculation based on re-measurement will not work in that situation.
By default, EncaptureMD will choose the most accurate method to calculate both end systolic and end diastolic volumes (ESV and EDV).
- Biplane is the most accurate
- 2,4 chamber is next
- Teiccholz is the least accurate method
- The Chosen values use the above 3 rules. It will always select the most accurate measurement provided. Chosen is what is reported.
SV =EDV-ESV.
CO = SV x HR.
CI = CO/BSA. (body surface area)
LVEF = SV/EDV