Agreement between preload reserve measured by impedance cardiography and echocardiography during pregnancy
Methods: In this prospective observational cross-sectional study, preload reserve was assessed by measuring the SV and CO during baseline and 90 s after PLR simultaneously by Doppler echocardiography and ICG in healthy pregnant women during the second and third trimesters. Bland–Altman analysis was used to determine the agreement between the two methods. Bias was calculated as the mean difference between two methods and precision as 1.96 SD of the difference.
Results: A total of 53 pregnant women were included. We found a statistically signifcant correlation between ΔSV (R=0.56, p<0.0001) and ΔCO (R=0.39, p=0.004) measured by ICG and Doppler echocardiography. The mean bias for ΔSV was 2.52 ml, with a precision of 18.19 ml. The mean bias for ΔCO was 0.21 l/min, with a precision of 1.51 l/min.
Conclusion: There was a good agreement and a statistically signifcant correlation between ICG and Doppler echocardiography for measuring preload reserve.