Fetal cardiac filling and ejection time fractions by pulsed‐wave Doppler: reference ranges and potential clinical application

Abstract

Objectives Fetal cardiac function can be evaluated using a variety of parameters. Among these, cardiac cycle time‐related parameters, such as filling time fraction (FTF) and ejection time fraction (ETF), are promising but rarely studied. We aimed to report the feasibility and reproducibility of fetal FTF and ETF measurements using pulsed‐wave Doppler, to provide reference ranges for fetal FTF and ETF, after evaluating their relationship with heart rate (HR), gestational age (GA) and estimated fetal weight (EFW), and to evaluate their potential clinical utility in selected fetal conditions. Methods This study included a low‐risk prospective cohort of singleton pregnancies and a high‐risk population of fetuses with severe twin–twin transfusion syndrome (TTTS), aortic stenosis (AoS) or aortic coarctation (CoA), from 18 to 41 weeks' gestation. Left ventricular (LV) and right ventricular inflow and outflow pulsed‐wave Doppler signals were analyzed, using valve clicks as landmarks. FTF was calculated as: (filling time/cycle time) × 100. ETF was calculated as: (ejection time/cycle time) × 100. Intraclass correlation coefficients (ICC) were used to evaluate the intra‐ and interobserver reproducibility of FTF and ETF measurements in low‐risk fetuses. The relationships of FTF and ETF with HR, GA and EFW were evaluated using multivariate regression analysis. Reference ranges for FTF and ETF were then constructed using the low‐risk population. Z‐scores of FTF and ETF in the high‐risk fetuses were calculated and analyzed. Results In total, 602 low‐risk singleton pregnancies and 54 high‐risk fetuses (nine pairs of monochorionic twins with severe TTTS, 16 fetuses with AoS and 20 fetuses with CoA) were included. Adequate Doppler traces for FTF and ETF could be obtained in 95% of low‐risk cases. Intraobserver reproducibility was good to excellent (ICC, 0.831–0.905) and interobserver reproducibility was good (ICC, 0.801–0.837) for measurements of all timing parameters analyzed. Multivariate analysis of FTF and ETF in relation to HR, GA and EFW in low‐risk fetuses identified HR as the only variable predictive of FTF, while ETF was dependent on both HR and GA. FTF increased with decreasing HR in low‐risk fetuses, while ETF showed the opposite behavior, decreasing with decreasing HR. Most recipient twins with severe TTTS showed reduced FTF and preserved ETF. AoS was associated with decreased FTF and increased ETF in the LV, with seemingly different patterns associated with univentricular vs biventricular postnatal outcome. The majority of fetuses with CoA had FTF and ETF within the normal range in both ventricles. Conclusions Measurement of FTF and ETF using pulsed‐wave Doppler is feasible and reproducible in the fetus. The presented reference ranges account for associations of FTF with HR and of ETF with HR and GA. These time fractions are potentially useful for clinical monitoring of cardiac function in severe TTTS, AoS and other fetal conditions overloading the heart. © 2020 International Society of Ultrasound in Obstetri...

Reference ranges for fetal cardiac, ventricular and atrial relative size, sphericity, ventricular dominance, wall asymmetry and relative wall thickness from 18 to 41 gestational weeks

“…This was a prospective cohort study of low‐risk singleton pregnancies attending the Maternal–Fetal Medicine Department at BCNatal in Barcelona (Hospitals Clínic and Sant Joan de Déu), Spain for routine obstetric care between 2014 and 2017. The same cohort was used previously to construct nomograms of fetal cardiac dimensions 12 and cardiac filling and ejection time fractions 23 . Exclusion criteria included fetal malformation, chromosomal abnormality and any clinical condition associated potentially with cardiovascular remodeling, such as conception by ART, maternal pregestational diabetes, chronic hypertension, antiretroviral treatment for HIV, pre‐eclampsia or small‐for‐gestational age (EFW < 10 th centile) at the time of the scan.…”

Effect of oval foramen restriction and premature contraction of the arterial catheter on right heart function of fetuses and infants

“…The longitudinal displacement of the sampling line and the tricuspid valve ring at the sampling point was less than 15°, which ensured the reliability of the measurement data. The Tei index can reflect the overall right heart function, with high sensitivity changes in the right heart function due to its good reproducibility, and it is unaffected by the angle of the sampling line and the flow direction ( Herling et al, 2019 ; Kang et al, 2021 ; Soveral et al, 2021 ). The Tei index has been widely used in the evaluation of adult right heart function.…”

Índice de rendimiento biventricular del corazón fetal

“…Además, algunas de ellas presentan ciertas limitaciones, como modalidad que evalúa solo la función sistólica o diastólica univentricular, fórmulas con dificultades en su aplicación que limitan su difusión, requerimiento de tecnología avanzada que no está disponible para todos lo que utilizan la ultrasonografía y, finalmente, la evaluación de la eficiencia y eficacia de las técnicas con referencia a su utilidad en la toma de decisiones clínicas. Los tiempos de llenado (diástole) y de eyección (sístole) pueden ser medidos mediante la flujometría Doppler (30)(31)(32)(33)(34)(35) , obteniendo las ondas de llenado ventricular (E y A) y las de eyección a través de las válvulas sigmoideas (TE).…”

“…Se ha evaluado la fracción de tiempos de llenado y vaciado en ambos ventrículos por separado (35) y en una población de bajo riesgo, encontrando que la FC es el único factor determinante. Estos autores concluyen que la FCF influye en ambos tiempos de llenado y vaciado, y que la relación edad gestacional, peso estimado, lo determina en bajo grado en la eyección; por lo tanto, la evaluación precisa del tiempo de llenado y vaciado debe incluir la FCF.…”