Novel Speckle Tracking Analysis Showed Excellent Reproducibility for Size and Shape of the Fetal Heart and Good Reproducibility for Strain and Fractional Shortening

Practical Evaluation of the Fetal Cardiac Function

The fetal heart adapts dynamically to nutrient and oxygen needs from all fetal organs. These continuous changes make it difficult to define normal/abnormal cardiac function based only on the evaluation of a few cycles. Many signs of fetal cardiac dysfunction have been suggested; however, very few can stand as true manifestations of cardiac deterioration, and none has emerged as a single reliable marker of cardiac dysfunction. It is the combination of abnormal findings that provides a more accurate assessment of the status of the fetal heart function.

Assessment of Fetal Ventricular Size and Shape in Women With Intrahepatic Cholestasis of Pregnancy Using Speckle Tracking

OBJECTIVE

To examine the effect of intrahepatic cholestasis of pregnancy (ICP) on fetal heart morphology.

METHODS

This case-control study was conducted with 40 women with ICP and 54 pregnant controls. Fetal heart quantification based on speckle tracking technology was used to assess the morphology of the fetal right and left ventricles. Routine ventricular size parameters, global and 24-segment spherical indices (SIs) were measured and compared between groups.

RESULTS

The routine fetal cardiac parameters, global and right-ventricular SIs did not differ between the ICP and control groups. The left-ventricular apical (segments 16-24) SIs were lower in the ICP group than in the control group (P < .05), with no significant difference in the other left-ventricular segments.

CONCLUSIONS

Subclinical morphological changes were observed in the left ventricular apical segments of the fetal hearts in women with ICP, which indicates an intrauterine environment with high bile acid concentrations. Twenty-four-segment SIs can be used to effectively evaluate these changes.

Evaluation of Fetal Heart Using Fetal Heart Quantification (fetalHQ) Technique in an Indian Cohort

OBJECTIVE

To evaluate the intra- and interobserver reproducibility of parameters used to determine cardiac morphometry and deformation using FetalHQ in Indian population.

METHODOLOGY

Two operators blinded to each other performed FetalHQ analysis independently on 35 normal fetuses of gestational age between 18 + 0 and 37 + 0 weeks and days. Intra- and interobserver correlation coefficient and limits of agreement were ascertained for parameters obtained from HQ analysis.

RESULTS

Excellent reproducibility (ICC > 0.9) was observed for global morphometric parameters. Ejection fraction, stroke volume, stroke volume/kg demonstrated excellent reliability (ICC > 0.9), cardiac output, fractional area change showed a lower correlation (ICC < 0.8), and right and left ventricular global strain showed no correlation. Twenty-four segment sphericity index of left ventricle (LV) and right ventricle (RV) showed low to moderate correlation (LV-ICC 0.48-0.79; RV-ICC 0.43-0.82). Fractional shortening (FS) showed poor intraobserver reliability in RV.

CONCLUSION

FetalHQ provides reliable estimates of the global cardiac morphometry but not for global cardiac strain. Regional transverse contractility represented by FS has poor correlation in right ventricle, especially in the apical region, possibly due to moderator band. Nevertheless, it is a promising tool which requires technical advancements and validation to improve its accuracy and reliability.

Reproducibility Analysis of Two Speckle Tracking Software for the Antenatal Semiautomated Assessment of the Fetal Cardiac Function

INTRODUCTION

Speckle tracking echocardiography is a non-Doppler modality allowing the semiautomated evaluation of the fetal cardiac function by tracking the speckles of the endocardial borders. Little evidence is available on the evaluation and comparison of different software for the functional assessment of the fetal heart by means of speckle tracking echocardiography. The aim of this study was to evaluate the reproducibility and agreement of two different proprietary speckle tracking software for the prenatal semiautomated assessment of the fetal cardiac function.

METHODS

The prospective study including non-anomalous fetuses was referred for different indications at two tertiary academic units in Italy (University of Parma) and Spain (University of Barcelona). Two-dimensional clips of the four-chamber view of the fetal heart were acquired by two dedicated operators using high-end ultrasound machines with a frame rate higher than 60 Hz. The stored clips were pseudo-anonymized and shared between the collaborating units. Functional echocardiographic analyses were independently performed using the two proprietary software (TomTec GmbH and FetalHQ®) by the same operators. Inter-software reproducibility of the endocardial global longitudinal strain (EndoGLS) and fractional area change (FAC) of the left (LV) and the right ventricles (RV) and ejection fraction (EF) of the LV were evaluated by the intraclass correlation coefficient (ICC).

RESULTS

Forty-eight fetuses were included at a median of 31+2 (21+6-40+3) gestational weeks. Moderate reproducibility was found for the functional parameters of the LV: EndoGLS (Pearson's correlation 0.456, p < 0.01; ICC 0.446, 95% CI: 0.189-0.647, p < 0.01); EF (Pearson's correlation 0.435, p < 0.01; ICC 0.419, 95% CI: 0.156-0.627, p < 0.01); FAC (Person's correlation 0.484, p < 0.01; ICC 0.475, 95% CI: 0.223-0.667, p < 0.01). On the contrary, RV functional parameters showed poor reproducibility between the two software: EndoGLS (Pearson's correlation 0.383, p = 0.01; ICC 0.377, 95% CI: 0.107-0.596, p < 0.01) and FAC (ICC 0.284, 95% CI: 0.003-0.524, p = 0.02).

CONCLUSION

Our results demonstrate a moderate reproducibility of the speckle tracking analysis of the LV using TomTec GmbH and FetalHQ®, with poor reproducibility for RV analysis.

Association of Amniotic Fluid Volume and Fetal Cardiac and Cerebrovascular Parameters in Fetal Growth Restriction

OBJECTIVES

To investigate the prevalence of oligohydramnios, brain sparing, and cardiac dysfunction among a cohort of fetal growth restriction (FGR).

METHODS

To assess the prevalence of oligohydramnios amongst a large sample of FGR fetuses, we screened a database of ultrasounds of FGR pregnancies from our maternal-fetal medicine clinics (clinical cohort) for diminished amniotic fluid volume. Using a threshold of a maximum vertical pocket (MVP) of <2 cm for "oligohydramnios," and 2 to 3 cm as a "reduced fluid" group, trends of Doppler values and cardiac parameters were assessed from pregnancies in an ongoing research study (comprehensive cohort).

RESULTS

In the clinical cohort, oligohydramnios was identified in only 2/229 (0.8%) and reduced fluid in 19/229 (8%). In the comprehensive cohort, oligohydramnios was seen in 3/126 (2.3%) and reduced fluid in 14/126 (11.1%). A high rate of cardiac and Doppler abnormalities were observed in the oligohydramnios group of the comprehensive cohort. The patients with oligohydramnios had a distinctly different cardiac phenotype with small (2/3 with cardiac area <5th%) (P = 0.01) and round (3/3 with global sphericity index <5th%) (P = 0.02) hearts.

CONCLUSION

Oligohydramnios, when present with FGR, is accompanied by high rates of cerebral and cardiovascular abnormalities.

How automated techniques ease functional assessment of the fetal heart: Applicability of two-dimensional speckle-tracking echocardiography for comprehensive analysis of global and segmental cardiac deformation using fetalHQ®

BACKGROUND

Prenatal echocardiographic assessment of fetal cardiac function has become increasingly important. Fetal two-dimensional speckle-tracking echocardiography (2D-STE) allows the determination of global and segmental functional cardiac parameters. Prenatal diagnostics is relying increasingly on artificial intelligence, whose algorithms transform the way clinicians use ultrasound in their daily workflow. The purpose of this study was to demonstrate the feasibility of whether less experienced operators can handle and might benefit from an automated tool of 2D-STE in the clinical routine.

METHODS

A total of 136 unselected, normal, singleton, second- and third-trimester fetuses with normofrequent heart rates were examined by targeted ultrasound. 2D-STE was performed separately by beginner and expert semiautomatically using a GE Voluson E10 (FetalHQ®, GE Healthcare, Chicago, IL). Several fetal cardiac parameters were calculated (end-diastolic diameter [ED], sphericity index [SI], global longitudinal strain [EndoGLS], fractional shortening [FS]) and assigned to gestational age (GA). Bland-Altman plots were used to test agreement between both operators.

RESULTS

The mean maternal age was 33 years, and the mean maternal body mass index prior to pregnancy was 24.78 kg/m2. The GA ranged from 16.4 to 32.0 weeks (average 22.9 weeks). Averaged endoGLS value of the beginner was -18.57% ± 6.59 percentage points (pp) for the right and -19.58% ± 5.63 pp for the left ventricle, that of the expert -14.33% ± 4.88 pp and -16.37% ± 5.42 pp. With increasing GA, right ventricular endoGLS decreased slightly while the left ventricular was almost constant. The statistical analysis for endoGLS showed a Bland-Altman-Bias of -4.24 pp ± 8.06 pp for the right and -3.21 pp ± 7.11 pp for the left ventricle. The Bland-Altman-Bias of the ED in both ventricles in all analyzed segments ranged from -.49 mm ± 1.54 mm to -.10 mm ± 1.28 mm, that for FS from -.33 pp ± 11.82 pp to 3.91 pp ± 15.56 pp and that for SI from -.38 ± .68 to -.15 ± .45.

CONCLUSIONS

Between both operators, our data indicated that 2D-STE analysis showed excellent agreement for cardiac morphometry parameters (ED and SI), and good agreement for cardiac function parameters (EndoGLS and FS). Due to its complexity, the application of fetal 2D-STE remains the domain of scientific-academic perinatal ultrasound and should be placed preferably in the hands of skilled operators. At present, from our perspective, an implementation into clinical practice "on-the-fly" cannot be recommended.

Feasibility and reliability of fetal two dimensional speckle tracking echocardiography at 16 weeks gestational age: A pilot study

BACKGROUND

Fetal two-dimensional speckle tracking echocardiography (2D-STE) is an emerging technique for assessing fetal cardiac function by measuring global longitudinal strain. Alterations in global longitudinal strain may serve as early indicator of pregnancy complications, making 2D-STE a potentially valuable tool for early detection. Early detection can facilitate timely interventions to reduce fetal and maternal morbidity and mortality. Therefore, the aim of this study was to investigate the feasibility of performing 2D-STE at 16 weeks gestational age.

METHODS

This pilot study utilized 50 ultrasound clips of the fetal four-chamber view recorded between 15+5 and 16+2 weeks gestational age from a prospective cohort study. A strict protocol assessed three parameters essential for 2D-STE analysis: fetal four-chamber view ultrasound clip quality, region of interest, and frame rates. Two independent researchers measured global longitudinal strain in all adequate fetal four-chamber view ultrasound clips to determine inter- and intra-operator reliability.

RESULTS

Out of the 50 ultrasound clips, 37 (74%) were feasible for 2D-STE analysis. The inter-operator reliability for global longitudinal strain measurements of the left and right ventricles was moderate (ICC of 0.64 and 0.74, respectively), while the intra-operator reliability was good (ICC of 0.76 and 0.79, respectively).

CONCLUSIONS

Our findings demonstrate that fetal 2D-STE analysis at 16 weeks gestational age is feasible when adhering to a strict protocol. However, further improvements are necessary to enhance the inter- and intra-operator reliability of 2D-STE at this gestational age.

Changes in the shape and function of the fetal heart of pre- and gestational diabetes mothers

BACKGROUND

Hyperglycemia during pregnancy can affect fetal heart in many ways, including causing cardiac malformation, leading to hypertrophic cardiomyopathy and cardiac dysfunction. Echocardiographic evaluation can assist identify alterations in heart structure, morphology and function, enabling prompt monitoring and management. However, according to earlier research, the cardiac alterations are modest in hyperglycemic mothers' fetuses, and might not be detectable using conventional methods and it is also unclear whether these changes are related to the metabolism of mothers. Fetal Heart Quantification (Fetal HQ) can assess ventricular geometry and function more sensitively and thoroughly, and identify sub-clinical cardiac dysfunction. The purpose of this study was to evaluate fetal heart by Fetal HQ in fetuses of hyperglycemic mothers who either had pre-gestational or gestational diabetes and to correlate them with maternal metabolic indices.

METHODS

The fetuses of 25 gestational age-matched control mothers, 48 women with gestational diabetes mellitus (GDM), and 11 women with diabetes mellitus (DM) were included in the prospective case-control research. Using fetal echocardiography and speckle tracking echocardiography (STE), the heart of the fetus was evaluated. Differences in the groups' anthropometric, metabolic, and cardiac parameters were examined. It was assessed whether maternal features, prenatal glucose, lipids, and maternal hemoglobin A1c (HbA1c) correlated with fetal cardiac parameters.

RESULTS

The LV EDV and ESV were significantly higher in the GDM group as compared to the DM group (p < 0.05). The GSI% was significantly lower in the GDM group compared with the control (p < 0.05). The LV SV and CO of the GDM group were both significantly higher compared with the DM group (p < 0.05). There was a significant decrease in RV FS for segments 1-7 in GDM fetuses compared to the control (p < 0.05) and for segments 5-10 compared to DM (p < 0.05). Fetal cardiac morphology and function indices correlate with maternal pregestational weight, BMI, early pregnancy fast glucose, lipids, and glycemic control levels.

CONCLUSIONS

Fetuses exposed to gestational diabetes have altered heart morphology and function that is linked to maternal metabolic parameters, which presents a special indication for performing geometry and function cardiac assessment. Fetal HQ can be employed to evaluate the fetal cardiac shape and function in fetuses exposed to gestational diabetes.

Abnormal Shape and Size of the Cardiac Ventricles Are Associated with a Higher Risk of Neonatal Death in Fetuses with Isolated Left Congenital Diaphragmatic Hernia

INTRODUCTION

The objective of this study was to evaluate the association between fetal cardiac deformation analysis (CDA) and cardiac function with severe adverse perinatal outcomes in fetuses with isolated left congenital diaphragmatic hernia (CDH).

METHODS

CDA in each ventricle (contractility, size, and shape), evaluated by speckle tracking and novel FetalHQ software, and markers of cardiac function (E/A ratios, pulmonary and aortic peak systolic velocities, and sigmoid annular valve diameters), were evaluated in fetuses with isolated left CDH. Two evaluations were performed: at referral (CDA and function) and within 3 weeks of delivery (CDA). Severe adverse neonatal outcomes were considered neonatal death (ND) or survival with CDH-associated pulmonary hypertension (CDH-PH). Differences and associations between CDA, cardiac function, and severe adverse outcomes were estimated.

RESULTS

Fifty fetuses were included, and seventeen (34%) had severe adverse neonatal outcomes (11 ND and 6 survivors with CDH-PH). At first evaluation, the prevalence of a small left ventricle was 34% (17/50) with a higher prevalence among neonates presenting severe adverse outcomes (58.8 [10/17] vs. 21.2% [7/33]; p = 0.01; OR, 5.03 [1.4-19.1; p = 0.01]) and among those presenting with neonatal mortality (8/11 [72.7] vs. 9/39 [23.0%]; p = 0.03; OR, 8.9 [1.9-40.7; p = 0.005]). No differences in cardiac function or strain were noted between fetuses with or without severe adverse outcomes. Within 3 weeks of delivery, the prevalence of small left ventricle was higher (19/34; 55.8%) with a more globular shape (reduced transverse/longitudinal ratio). A globular right ventricle was significantly associated with ND or survival with CDH-PH (OR, 14.2 [1.5-138.3]; p = 0.02).

CONCLUSION

Fetuses with isolated CDH at risk of perinatal death or survival with CDH-PH had a higher prevalence of a small left ventricle and abnormal shape of the right ventricle.

Advanced imaging of fetal cardiac function

Over recent decades, a variety of advanced imaging techniques for assessing cardiovascular physiology and cardiac function in adults and children have been applied in the fetus. In many cases, technical development has been required to allow feasibility in the fetus, while an appreciation of the unique physiology of the fetal circulation is required for proper interpretation of the findings. This review will focus on recent advances in fetal echocardiography and cardiovascular magnetic resonance (CMR), providing examples of their application in research and clinical settings. We will also consider future directions for these technologies, including their ongoing technical development and potential clinical value.

Cardiac Size, Shape, and Ventricular Contractility in Fetuses at Sea Level With an Estimated Weight Less-than 10th Centile

OBJECTIVES

To investigate cardiac size, shape, and ventricular contractility in fetuses with estimated fetal weight (EFW) <10th centile at sea level (Houston).

METHODS

A prospective ultrasound study examined 37 fetuses with EFW <10th centile at sea level. High-frequency cine clips were used to evaluate the 4-chamber view including end-diastolic measurements and global sphericity index. The size, shape, and contractility of both ventricles were analyzed with speckle tracking methods. Z scores were calculated using the mean ± standard deviation (SD) derived from normal controls. Measurements were abnormal if their Z score values were <-1.65 or >+1.65. The proportion of small fetuses with abnormal parameters was compared to normal reference ranges. Results were compared to a similar published study of small fetuses at higher altitude in Denver.

RESULTS

About one-third of Houston fetuses with EFW <10th centile had enlarged globular shaped 4-chamber hearts with increased right ventricle (RV) area, RV basal-apical length, RV base width, and left ventricle (LV) basal-apical length measurements. Bilateral ventricular hypertrophy was often present. An increased proportion of Houston fetuses had increased ventricular contractility. However, decreased ventricular contractility was more prevalent for higher altitude fetuses.

CONCLUSIONS

Third trimester fetuses at sea level, with an EFW <10th centile, were often associated with enlarged and globular-shaped hearts. They had increased global and longitudinal ventricular contractility as compared to controls. Higher altitude fetuses also had enlarged globular-shaped hearts but with a greater proportion of cases having decreased ventricular contractility as compared to the sea level cohort.

Feasibility of 4D-Spatio Temporal Image Correlation (STIC) in the Comprehensive Assessment of the Fetal Heart Using FetalHQ®

Fetal Heart Quantification (FetalHQ®) is a novel speckle tracking software that permits the study of global and regional ventricular shape and function from a 2D four-chamber-view loop. The 4D-Spatio Temporal Image Correlation (STIC) modality enables the offline analysis of optimized and perfectly aligned cardiac planes. We aimed to evaluate the feasibility and reproducibility of 4D-STIC speckle tracking echocardiography (STE) using FetalHQ® and to compare it to 2D STE. We conducted a prospective study including 31 low-risk singleton pregnancies between 20 and 40 weeks of gestation. Four-chamber view volumes and 2D clips were acquired with an apex pointing at 45° and with a frame rate higher than 60 Hz. Morphometric and functional echocardiography was performed by FetalHQ®. Intra- and interobserver reproducibility were evaluated by the intraclass correlation coefficient (ICC). Our results showed excellent reproducibility (ICC > 0.900) for morphometric evaluation (biventricular area, longitudinal and transverse diameters). Reproducibility was also good (ICC > 0.800) for functional evaluation (biventricular strain, Fractional Area Change, left ventricle volumes, ejection fraction and cardiac output). On the contrary, the study of the sphericity index and shortening fraction of the different ventricular segments showed lower reproducibility (ICC < 0.800). To conclude, 4D-STIC is feasible, reproducible and comparable to 2D echocardiography for the assessment of cardiac morphometry and function.