Using speckle-tracking echocardiography to assess fetal myocardial deformation: are we there yet? Yes we are!

Clinical Application of the Fetal HQ Technique in the Evaluation of Normal Fetal Cardiac Function at Different Gestational Weeks

OBJECTIVES

To investigate the clinical value of fetal heart quantification (fetal HQ) in the evaluation of normal fetal heart size, morphology, and cardiac function at different gestational weeks.

MATERIALS AND METHODS

A total of 101 pregnant women diagnosed with a healthy fetus by fetal echocardiography from September 2021 to December 2023 were selected and classified into four different periods of gestational weeks: 20-28 weeks (25 cases), 29-32 weeks (26 cases), 33-36 weeks (26 cases), and 37-40 weeks (24 cases). Quantitative analyses were performed by automatically tracking the endocardium using fetal HQ software that comes with the Voluson E10 from GE. To investigate the correlation between four-chambered vesicle length end-diastolic (4CV LED), four-chambered vesicle transverse width end-diastolic (4CV TWED), global sphericity index (GSI), ejection fraction (EF), stroke volume (SV), cardiac output (CO), and gestation age (GA), and the variability of normal fetal cardiac morphology and cardiac function at different gestational weeks.

RESULTS

A statistically significant difference was observed between 4CV LED and 4CV TWED in normal fetuses at different gestational weeks (p < 0.05), which exhibited a positive correlation with gestational week. Conversely, no significant correlation was identified between GSI and gestational week (p > 0.05). The mean GSI of 101 normal fetuses was found to be 1.25 ± 0.09. A comparative analysis of EF, SV, and CO in normal fetuses at different gestational weeks revealed statistically significant differences in SV and CO (p < 0.05), which gradually increased with gestational weeks, whereas there was no statistically significant difference in EF (p > 0.05).

CONCLUSIONS

Fetal HQ represents a straightforward and dependable method for evaluating GSI and 24-segment SI of the left and right ventricles, which can provide a certain theoretical basis for the clinical quantitative evaluation of fetal cardiac geometry and cardiac function.

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.

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.

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.

Comparing the Non-Quiver and Quiver Techniques for Identification of the Endocardial Borders Used for Speckle-Tracking Analysis of the Ventricles of the Fetal Heart

This study compared the non-quiver with the quiver technique for identifying the end-systolic and end-diastolic endocardium of the fetal right ventricle (RV) and left ventricle (LV) used for speckle-tracking analysis. Bland-Altman and t test analyses showed no significant differences in measurements between the techniques for the RV and LV. The difference in the time required to perform the non-quiver analysis was significantly longer (P < .001) for the RV and LV than the quiver technique. The quiver technique allows the examiner to efficiently identify the endocardial borders of the fetal heart compared with the non-quiver method.