Comparison of bioreactance and echocardiographic non-invasive cardiac output monitoring and myocardial function assessment in primagravida women

Abstract Background Non-invasive cardiac output monitoring (NICOM) using bioreactance (BRT) in pregnancy is gaining interest but lacks validation. We compared simultaneous cardiac output (CO) measurements obtained using the NICOM ® (BRT-CO) and echocardiography (echo-CO), and assessed the relationship between maternal characteristics and myocardial performance. Methods Paired stroke volume (SV) and CO readings were obtained using NICOM ® and echocardiography, in a group of healthy nulliparous women throughout a 15 min period. Agreement between NICOM ® and echocardiography was assessed using Bland–Altman analysis and the intraclass correlation coefficient (ICC). Left ventricular (LV) function was assessed using systolic strain and tissue Doppler velocities (S′, E′, and A′ waves). Results Thirty-five women with a median [interquartile range] age, weight, and gestation of 29 [26–34] yr, 71 [64–79] kg, and 28 [21–29] weeks, respectively, were enrolled. There was good agreement between NICOM ® -measured and echocardiographically measured SV [mean bias 6 ml (limits of agreement −18 to 29); ICC 0.8 (95% confidence interval 0.6–0.9), P P −1 . The mean (sd) LV strain was −18.6 (2.6)%. There was a negative relationship between BMI and LV diastolic function measured using the E′:A′ ratio ( r  = −0.51, P Conclusions Stroke volume and CO measurements obtained using NICOM ® were comparable to those obtained using echocardiography, with acceptable limits of agreement. Increased maternal BMI negatively impacts LV diastolic function measured using tissue Doppler imaging.