Myocardial strain assessment using velocity vector imaging in normally grown fetuses at term

Objectives To assess prospectively fetal myocardial deformation at term in normally grown fetuses using the velocity vector imaging (VVI) two-dimensional speckle-tracking technique, and to explore myocardial deformation changes over the last 4 weeks of pregnancy. Methods This was a prospective, observational cohort study of 276 women with an uncomplicated singleton pregnancy who underwent fortnightly ultrasound from 36 weeks' gestation until delivery at the Mater Mother's Hospital, Brisbane, Australia. Fetal myocardial deformation (assessed by global and segmental longitudinal systolic myocardial strain and strain rate of both right and left ventricles) was measured using VVI software. Results Mean global longitudinal left and right ventricular strain and strain rate values decreased between each time point. At 36, 38 and 40 weeks' gestation, left ventricular global strain (%) and strain rate (/s) decreased, respectively, as follows: -14.6 +/- 3.8% and -1.2 +/- 0.3/s at 36 weeks; -13.6 +/- 3.3% and -1.1 +/- 0.3/s at 38 weeks; and -12.3 +/- 3.1% and -1.0 +/- 0.3/s at 40 weeks. At 36, 38 and 40 weeks, mean right ventricular global strain (%) and mean strain rate (/s) decreased, respectively, as follows: -14.2 +/- 3.4% and -1.2 +/- 0.2/s at 36 weeks; -13.4 +/- 3.0% and -1.1 +/- 0.2/s at 38 weeks; and -12.8 +/- 2.8% and -1.1 +/- 0.2/s at 40 weeks. Conclusions Global ventricular strain values diminish with advancing gestational age. Myocardial deformation imaging is feasible in late gestation and may be useful as an adjunct for the assessment of fetal cardiac function close to birth. Copyright (c) 2017 ISUOG. Published by John Wiley & Sons Ltd.