Assessment of diastolic function of normal fetal heart using dual-gate Doppler.
OBJECTIVES
The ratio of mitral peak early diastolic filling to early diastolic mitral annular velocity (E/e') reflects diastolic cardiac function in adults. Dual-gate Doppler (DD) enables measurements of E/e' in the same heart beat. This study was designed to assess the utility of the DD method for measurement of fetal E/e' and determine reference ranges for normal fetuses.


METHODS
This prospective study comprised normal singleton pregnancies undergoing fetal echocardiography between 16 and 36 weeks of gestation. According to the DD method, E-wave velocity on pulsed-wave Doppler and e'-wave on tissue Doppler imaging were measured simultaneously on an apical or basal four-chamber view, and fetal E/e' was calculated. Spearman's correlation coefficient was used to assess the relationship between gestational age (GA) and E-wave and e'-wave velocities and E/e'.


RESULTS
A total of 133 pregnancies were included in this study and all E/e' measurements were successful. Significant correlation was observed between GA and both left ventricular (LV) E/e' (r s  = -0.666, P < 0.001) and right ventricular (RV) E/e' (r s  = -0.607, P < 0.001). The regression equations for bilateral E/e' were: LV-E/e' = 17.341 - 0.631GA + 0.008 × GA2 (mean ± SD, R 2  = 0.440 ± 1.333); and RV-E/e' = 19.156 - 0.794GA + 0.012GA2 (R 2  = 0.419 ± 1.329).


CONCLUSIONS
Bilateral E/e' of normal fetuses, measured using the DD method, decreased with GA, which is considered to be related to myocardial maturity. DD is a useful and convenient method for evaluating fetal E/e' in order to assess diastolic function in the prenatal period. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
['Takano|M|M|http://orcid.org/0000-0002-0512-1173', 'Nakata|M|M|', 'Nagasaki|S|S|', 'Ueyama|R|R|', 'Morita|M|M|']
D001783:Blood Flow Velocity D003971:Diastole D015150:Echocardiography, Doppler D005260:Female D047109:Fetal Development D005318:Fetal Heart D005333:Fetus D005865:Gestational Age D006801:Humans D011247:Pregnancy D011446:Prospective Studies D012016:Reference Values D016216:Ultrasonography, Prenatal
diastolic function tissue Doppler imaging E/e′ dual-gate Doppler method fetal cardiac function