Left Ventricular Ejection Fraction: Calculation Methods and Norms
Definition
LVEF is the proportion of blood volume ejected by the left ventricle into the aorta per cardiac cycle. Ejection fraction is the most widely used echocardiographic indicator for monitoring global systolic function of the left ventricle. Very often, LVEF is assessed visually (movement of each wall in each section followed by a mental compilation of information in a 'bull's eye' manner).
Recommended Method: Biplane Method of Disks (Modified Simpson)
LVEF should be calculated using the biplane method of Simpson from 2D volumes (EDV and ESV) obtained from apical 4- and 2-chamber views. It is crucial that LVEF values are not derived from foreshortened or poorly visualized volume data. If accurate calculation is not possible, echocontrast may be used; if calculation of LVEF by the biplane method of disks is still not possible with contrast, CMR is recommended (Plana et al., 2014).
Linear methods for calculating EDV and ESV by Teicholz and Quinones are no longer recommended. They can only be used when there are no local contractility disturbances of the left ventricle and/or there is diffuse hypokinesis of the walls. In all other cases, echovolumetric methods (Bullet or method of disks) should be used.
Teicholz Method
The Teicholz method assessed contractility only of the basal segments. If there is a contractility disturbance only at the mid-level or apex, this method will not account for global systolic function.
Algorithm: measure LVIDd and LVIDs; LVIDd³ = LVIDV (diastolic volume), LVIDs³ = LVISV (systolic volume).
EF% = (LVIDd³ − LVIDs³) / LVIDd³ × 100%. Normal EF% values are 53–73% (20+ years).
Quinones Method
The method allows calculation of LVEF considering the contractility features of the apex:
EF% = [(LVIDd² − LVIDs²) / LVIDd²] × 100% + K, where K is the correction factor for apical contractility.
| Apical Condition | Coefficient K |
|---|---|
| Normal contractility | +10% |
| Hypokinesis | +5% |
| Akinetic | +0% |
| Dyskinesis | −5% |
| Aneurysm | −10% |
Normal LVEF values by Quinones >55–65%.
LVEF Norms (BSE, 2020)
BSE maintains unified reference intervals for men and women. In the NORRE dataset, a statistically significant difference between genders was identified: the lower reference limit for men was 53.5%, for women — 54.5% (P = 0.009).
Related Hemodynamic Indicators
Stroke volume: SV = EDV − ESV (normal 70–100 ml). Cardiac output: CO = SV × HR (normal 4–8 l/min). Cardiac index: CI = CO / BSA (normal 3–4 l/min/m²). Heart rate — 60–100 bpm.
Special Situations
In patients with LVAD, the Quinones method is used with the assumption of an akinetic apex due to the presence of an apical inflow cannula. Fractional shortening (FS = [(LVIDd − LVIDs)/LVIDd]) reflects only regional function of the basal segments and radial thickening; in cases of regional contractility disturbances, it cannot be used as a measure of global function. In oncology patients, recommendations suggest calculating EF rather than FS.
Частые вопросы
What is the preferred method for calculating LVEF?
The biplane method of disks (modified Simpson) from 2D volumes of EDV and ESV obtained from apical 4- and 2-chamber views.
When are linear methods (Teicholz, Quinones) permissible?
Only in the absence of local contractility disturbances of the left ventricle and/or in cases of diffuse wall hypokinesis. In other cases, echovolumetric methods (Bullet or method of disks) are used.
What are the norms for LVEF?
By Teicholz — 53–73% (20+ years), by Quinones — >55–65%. According to BSE (2020), the lower reference limit is 53.5% for men, 54.5% for women.
What is the advantage of the Quinones method over Teicholz?
The Quinones method considers the contractility features of the apex through a correction factor K, whereas Teicholz assesses only the basal segments.
What to do if LVEF calculation by the biplane method is not possible?
Echocontrast may be useful; if calculation is still not feasible with contrast, CMR is recommended (Plana et al., 2014).