Published in:
Open Access 01-12-2023 | Transthoracic Echocardiography | Research
A method for calculating left ventricular ejection fraction noninvasively from left ventricular arterial coupling (Ees/Ea)
Published in: BMC Anesthesiology | Issue 1/2023
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Background
Ejection fraction (EF), which is assessed using ultrasonography, is a standard parameter for evaluating cardiac function in clinical cardiology and for cardiovascular management during general anesthesia. However, it is impossible to continuously and non-invasively assess EF using ultrasonography. The aim of our study was to develop a method for estimating EF non-invasively using the left ventricular arterial coupling ratio (Ees/Ea).
Methods
Ees/Ea was estimated non-invasively using the parameters pre-ejection period (PEP), ejection time (ET), end-systolic pressure (Pes) and diastolic pressure (Pad), which were calculated from a vascular screening system, VeSera 1000/1500 (Fukuda Denshi Co., Ltd., Tokyo, Japan). Then, left ventricular efficiency (Eff) as a pump, defined as the ratio of external work (EW) to myocardial oxygen consumption, which strongly correlates with the pressure-volume area (PVA), was calculated by a new formula using Ees/Ea, and was used to approximate EF (EFeff). Simultaneously, we measured EF using transthoracic echocardiography (EFecho), and compared it with EFeff.
Results
The study included 44 healthy adults (36 males, 8 females), in whom mean EFecho was 66 ± 5% and EFeff was 57 ± 9%. We found a positive correlation between EFecho and EFeff (R2 = 0.219, p < 0.05) on Bland-Altman analysis, with limits of agreement of – 7.5 to 24.4%, and percentage error of 24%.
Conclusion
The results suggest that EF can be measured non-invasively using left ventricular arterial coupling.