Characterization of Ventricular Myocardial Performance in the Fetus by Tissue Doppler Imaging

Abstract

Clinically useful indices of fetal cardiac function have not been fully delineated for tissue Doppler imaging (TDI). In the present study, 56 pregnancies between the 17(th) and 38(th) weeks of gestation included 38 normal fetuses, 6 cases of hydrops fetalis (HF), and 12 of intrauterine growth retardation (IUGR). Peak velocity in early diastole (E) was measured by pulsed-wave Doppler and the peak annular velocities in systole (Sa) and early diastole (Ea) were measured by TDI. The ratio between flow velocity and annular velocity in early diastole (E/Ea) and the ratio of the Sa of right ventricle to that of the left ventricle (RVSa/LVSa) were estimated. In all fetuses with HF, LVSa was <2 cm/s and LVE/Ea was >13. RVSa/LVSa in the HF group was significantly higher than that in the normal group, and RVSa/LVSa in the IUGR group was significantly lower than that in the normal group. A combination of low LVSa and high LVE/Ea shows reduced global myocardial performance of the LV, and would be one of the useful indices for quantitative assessment in high-risk pregnancies. Changes in the RVSa/LVSa ratio may reflect afterload changes in both ventricles and compensatory cardiovascular mechanisms occurring during the process of placental insufficiency and heart failure.