Related Experiment Video
Updated: Apr 3, 2026
Lumped-Parameter and Finite Element Modeling of Heart Failure with Preserved Ejection Fraction
Published on: February 13, 2021
First-phase ejection fraction and ventricular-arterial coupling across the lifespan: An in silico analysis
Edouard Long1,2, Jose L Flores-Guerrero2,3,4
1Faculty of Life Sciences and Medicine, King's College London, London, UK.
Insights
First-phase ejection fraction (EF1) is a novel cardiovascular metric outperforming standard left ventricular ejection fraction (LVEF). EF1 shows strong association with myocardial contractility and minimal influence from afterload in healthy adults.
Area of Science:
- Cardiovascular Physiology
- Biomedical Engineering
- Computational Biology
Background:
- First-phase ejection fraction (EF1) exhibits prognostic value in cardiovascular diseases, exceeding conventional left ventricular ejection fraction (LVEF).
- EF1's characteristics in healthy individuals remain largely uninvestigated.
- Understanding EF1 in a healthy cohort is crucial for its clinical application.
Purpose of the Study:
- To characterize first-phase ejection fraction (EF1) in a large cohort of healthy adults.
- To compare EF1 with left ventricular ejection fraction (LVEF) regarding age dependency and correlation with contractility and afterload.
- To evaluate EF1's potential as an afterload-independent measure of myocardial contractility.
Main Methods:
- Analysis of an in silico cohort of 3837 healthy adults (25-75 years old).
- Derivation of EF1 from aortic flow waves and left ventricular ejection fraction (LVEF) from pressure-volume loops.
- Quantification of correlations using Pearson's coefficient and assessment of determinants using linear regression, adjusted for age and heart rate.
Main Results:
- Mean EF1 was 50 ± 3% compared to LVEF of 67 ± 2%.
- EF1 demonstrated less influence from age (β: 0.09) than LVEF (β: -0.27).
- EF1 correlated strongly with contractility (Ees; r: 0.72) and minimally with afterload (Ea; r: -0.10), unlike LVEF (Ees: r: 0.46; Ea: r: -0.37).
Conclusions:
- First-phase ejection fraction (EF1) is strongly associated with myocardial contractility.
- EF1 exhibits a negligible relationship with afterload, suggesting it is an afterload-independent measure.
- EF1 holds potential as a sensitive indicator of myocardial contractility in clinical settings.
Abstract:
First-phase ejection fraction (EF1), the left ventricular ejection fraction (LVEF) up to maximal ventricular fiber shortening, has shown strong prognostic value in cardiovascular diseases, outperforming conventional LVEF, but remains uncharacterised in healthy individuals. An in silico cohort of healthy adults (n = 3837), from 25 to 75 years old was analyzed, showing good agreement with in vivo data. EF1 was derived from aortic flow waves as the proportion of end-diastolic volume ejected up to peak aortic flow. Contractility (Ees) and afterload (Ea) were derived from pressure-volume loops. Correlations were quantified using Pearson's coefficient and determinants were assessed using linear regression, adjusted for age and heart rate. Mean EF1 was 50 ± 3% versus LVEF 67 ± 2%, and EF1 was less influenced by age (β: 0.09 [95% confidence interval] [0.05, 0.12] vs. β: -0.27 [-0.30, -0.23]). EF1 correlated strongly with Ees compared to LVEF (r: 0.72 vs. 0.46, p < 0.001) and showed minimal correlation with Ea in contrast to LVEF (r: -0.10 vs. -0.37, p < 0.001). In regression, β was larger for Ees and Ea/Ees, and Ea smaller, in EF1 compared to LVEF. In conclusion, EF1 demonstrated a strong association with contractility and a negligible relationship with afterload, highlighting its potential as a sensitive, afterload-independent measure of myocardial contractility.
