Intervendor Discordance of Fetal and Neonatal Myocardial Tissue Doppler and Speckle-Tracking Measurements

Two-dimensional Speckle Tracking Echocardiography and Fetal Cardiac Performance During Fetoscopic Repair of Myelomeningocele

OBJECTIVE

No clinical standard exists for intraoperative fetal cardiac monitoring during maternal-fetal surgery for fetal myelomeningocele (fMMC). This pilot study explores the feasibility of using speckle tracking echocardiography (STE)-derived functional measurements to characterize cardiac performance throughout fetoscopic fMMC and compares these measures with other common intraoperative cardiac function parameters.

METHODS

Continuous fetal echocardiography was performed during fetoscopic fMMC repair with fetal heart rate assessment every 2 minutes and a 4-chamber cine clip and mitral and tricuspid Doppler inflow patterns captured every 5 minutes. Offline postprocessing was used to measure functional data during fetal surgery including left ventricle (LV) global longitudinal strain (GLS), right ventricle (RV) GLS, LV ejection fraction (EF), and RV fractional area of change (FAC). Interrater agreement was determined for all measurements.

RESULTS

Intraoperative fMMC echocardiograms were successfully obtained and analyzed for twenty patients. LV and RV GLS remained stable with a population average of -25.9±2.6% and -23.1±2.0% respectively during fMMC, and comparable to published normative ranges. Cardiac systolic and diastolic function was preserved at all surgical stages as demonstrated by LV EF, RV FAC, and spectral Doppler measurements. Interrater agreement for the spectral Doppler measurements was high, whereas STE agreement was low.

CONCLUSION

Fetal cardiac image acquisition for STE analysis was feasible during all stages of fetoscopic fMMC repair. Poor interrater agreement and offline post-processing limit the utility of STE for real-time clinical assessment, yet with experienced operators it could serve as a useful tool for scientific innovation to better understand modifiers of intraoperative fetal cardiac function.

The Effect of Smoothing and Drift Compensation on Fetal Strain

OBJECTIVE

The aim of this study was to assess the effect of user-regulated image-processing settings (spatial smoothing, temporal smoothing and drift compensation) on fetal left ventricular strain.

METHODS

Left ventricular average longitudinal strain was acquired from the four-chamber view of the fetal heart from 34 fetuses, with 30 fetuses presenting adequate quality. A total of 18 different settings for spatial smoothing, temporal smoothing and drift compensation were examined. At each setting the average strain for the 30 fetuses was calculated, whereby one could examine whether there was an average difference in fetal strain at the different settings. Furthermore, the difference between the highest and lowest strain values across the 18 settings was assessed for each fetus (min-max difference). The average min-max difference was then calculated across the 30 fetuses to calculate the mean discrepancy in fetal strain due to smoothing settings.

RESULTS

The average effect of the smoothing settings as well as drift compensation by them was small. However, when examining the discrepancy induced by the different settings together, they induced average proportional differences of approximately 18% for the endocardial and epicardial layers and 15% for the mid-wall layer.

CONCLUSION

This study shows that while the average effect of different smoothing settings and drift compensation was small, they induced significant discrepancy in strain values on the individual level. We recommend that examiners be consistent with regard to smoothing and drift compensation settings.

Development of the fetal myocardium and changes in myocardial fibers orientation

BACKGROUND AND AIMS

The mature left ventricular myocardium is arranged in a complex three-dimensional network of fibers that form a counterclockwise helix in the endocardial layer and a clockwise helix in the epicardial layer. There are no data in the literature on the development of left ventricular myocardium during the fetal life. The aims of this paper were to study the physiological maturation steps of the LV myocardium in fetuses from 17 to 40 gestational weeks, by means of speckle tracking applied to the endocardial and epicardial aspect of the left ventricle, and, to confirm our finds, through the histologic study of the myocardium of demised fetuses.

METHODS AND RESULTS

We studied longitudinal endocardial and epicardial strain by echocardiography in 105 fetuses. Twenty non-diseased fetal hearts from autopsies were selected to assess the layer thickness and cardiac fiber orientation in relation to gestational age. Echocardiography showed a progressive increasing of epicardial/endocardial longitudinal strain ratio with gestational age (r=0.51; p<0.0001). The strain rate E/A ratio increased over time (r=0.27; p=0.018). Histological data revealed that during the same gestational period, the proportion of the epicardial layer increased fourfold, the mesocardiac layer decreased and the endocardial layer remained stable. We found an excellent correlation between the epicardial to endocardial strain ratio and epicardial to endocardial wall thickness (r=0.950, p<0.001).

CONCLUSIONS

Left ventricular myocardium maturation begins early during fetal life. As the fetus develops, both the relative tissue volume and peak systolic strain rates shift together from the endocardium towards the epicardium. It is a slow process, completed late in fetal life.

Speckle Tracking Echocardiography in Twin Pregnancies and the Role of Global Longitudinal Strain and Peak Systolic Strain: A Systematic Review and Meta-Analysis

INTRODUCTION

Twin pregnancies are associated with an increased risk of perinatal morbidity and mortality. Pregnancy complications related to twins, such as fetal growth restriction, and twin-to-twin transfusion syndrome (TTTS), are associated with hemodynamic changes in the fetal heart. Two-dimensional speckle tracking echocardiography (2D STE) is a tool to evaluate fetal cardiac function. This paper aims to review the literature regarding global longitudinal strain (rate) and peak systolic strain (rate) assessed with 2D STE in twin pregnancies. Feasibility, frame rate, and angle of the fetal heart at the time of measurement were selected as secondary outcomes.

METHODS

The databases Medline, Embase, Scopus, and Web of Science were searched.

RESULTS

Seven articles met the inclusion criteria and selected all monochorionic diamniotic (MCDA) twins with TTTS as the study population. The global longitudinal strain in the right and left ventricle and the peak systolic strain in the right ventricle of the recipient MCDA twin are significantly decreased compared to the donor MCDA twin. 2D STE assessment was shown feasible and reproducible in MCDA pregnancies. Large heterogeneity in technical characteristics between the articles induces inconsistent results.

CONCLUSION

Although feasible, the knowledge of 2D STE is very limited in twin pregnancy. Prospective studies are needed to evaluate the 2D STE assessment in uncomplicated twin pregnancies considering its possible additive value in the diagnostics of pregnancy-related pathologies.

Perinatal Cardiac Functional Adaptation in Hypoplastic Left Heart Syndrome: A Longitudinal Analysis

BACKGROUND

The perinatal transition is characterized by acute changes in cardiac loading. Compared with normal newborn combined cardiac output (CCO), single right ventricular (RV) output of neonates with hypoplastic left heart syndrome (HLHS) is markedly greater. The aim of this study was to examine the mechanisms of cardiac adaptation that facilitate this perinatal transition from late fetal to early neonatal life in HLHS.

METHODS

Prospectively recruited pregnancies complicated by fetal HLHS (n = 35) and healthy control subjects (Ctrl; n = 17) underwent serial echocardiography in late gestation (38 ± 1 weeks) and 6, 24, and 48 hours after birth. Cardiac function was assessed using conventional, Doppler tissue, and speckle-tracking echocardiography.

RESULTS

Term fetuses with HLHS had RV output comparable with Ctrl CCO via higher stroke volume. Compared with both left ventricular and RV indices of Ctrl, they exhibited globular and dilated right ventricles with reduced relative wall thickness (0.40 ± 0.08 vs 0.49 ± 0.10, P < .01), increased Tei index' (HLHS vs Ctrl left ventricle/Ctrl right ventricle: sphericity index, 0.9 ± 0.25 vs 0.5 ± 0.10/0.6 ± 0.11; RV area index, 28 ± 6 vs 15 ± 3/17 ± 5 cm2/m2; Tei index', 0.65 ± 0.11 vs 0.43 ± 0.07/0.45 ± 0.09; P < .0001 for all). Neonates with HLHS generated elevated RV cardiac output compared with Ctrl CCO via higher heart rate and stroke volume, with further RV dilatation, increased longitudinal systolic strain at 48 hours (-17 ± 4% vs -14 ± 3%/ 14 ± 5%) with reduced circumferential and rotational myocardial deformation and altered diastolic function. Neonates with HLHS also demonstrated right atrial enlargement with increased longitudinal strain: 6 hours (33 ± 12% vs 26 ± 6%), 24 hours (37 ± 15% vs 26 ± 13%), and 48 hours (38 ± 11% vs 24 ± 13%) (P < .0001).

CONCLUSIONS

Term fetuses with HLHS exhibit altered RV geometry and RV systolic and diastolic functional parameters. After birth, further alterations in these cardiac parameters likely reflect adaptation to acutely altered RV loading from increasing cardiac output and pulmonary artery flow demands.

Increased preload and echocardiographic assessment of diastolic function

AIMS

Echocardiographic diastolic parameters are used to diagnose and monitor increased left ventricular filling pressure (LVFP) and we hypothesized that increased loading conditions cause increased E/e'. Our aim was to assess the effect of preload augmentation on diastolic parameters among both healthy subjects and subjects with known cardiac disease.

METHODS AND RESULTS

We included 129 subjects merged from two cohorts; one dialysis cohort (n = 47) and one infusion cohort (n = 82). Echocardiography was performed immediately before and after hemodialysis (HD) or saline infusion, under low and high loading conditions. Elevated LVFP was defined as septal E/e' ≥ 15 and/or lateral E/e' ≥ 13 at high-loading conditions. The population was divided according to elevated LVFP (n = 31) and normal LVFP (n = 98). The load difference for the population was 972 ± 460 mL, with no differences in load difference between elevated and normal LVFP (p NS). The subjects with elevated LVFP were older (63 ± 11 vs. 46 ± 16 years, p < .001), and had lower LV ejection fraction (50 ± 14 vs. 59 ± 8.1%, p < .01). After augmented preload, EDV increased in the normal LVFP group (p < .01) but remained unchanged in the elevated LVFP group (p NS). Both E and e' increased among the subjects with normal LVFP, whereas E/e' remained unchanged (∆E/e' +.1 [-.5-1.2]), p NS). Among the subjects with elevated, LVFP we observed increased E but not e', resulting in significantly increased E/e' (∆ average E/e' +2.4 [0-4.0], p < .01).

CONCLUSION

Augmented preload does not seem to affect E/e' among subjects with normal LVFP, whereas E/e' seems to increase significantly among subjects with elevated LVFP.

Increasing region of interest width reduces neonatal circumferential strain

OBJECTIVE

There is growing interest in speckle tracking echocardiography-derived strain as a measure of left ventricular function in neonates. However, knowledge gaps remain regarding the effect of image acquisition and processing parameters on circumferential strain measurements. The aim of this study was to evaluate the effect of using different region of interest (ROI) widths on speckle tracking derived circumferential strain in healthy neonates.

METHODS

Thirty healthy-term-born neonates were examined with speckle-tracking echocardiography in the short-axis view. Circumferential strain values were acquired and compared using two different ROI widths. Furthermore, strain values in the different vendor-defined wall layers were also compared.

RESULTS

Increasing ROI width led to a decrease in global circumferential strain (GCS) in the midwall and epicardial layers, the respective decreases in strain being -23.4 ± .6% to -22.0 ± 1.1%, p < .0001 and 18.5 ± 1.7% to -15.6 ± 2.0%, p < .0001. Segmental analyses were consistent with these results, apart from two segments in the midwall. There was no statistically significant effect on strain for the endocardial layer. A gradient was seen where strain increased from the epicardial to endocardial layers.

CONCLUSION

Increasing ROI width led to a decrease in GCS in the midwall and epicardium. There is an increase in circumferential strain when moving from the epicardial toward the endocardial layer. Clinicians wishing to implement circumferential strain into their practice should consider ROI width variation as a potential confounder in their measurements.

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.

Myocardial Function in Fetuses with Congenital Cytomegalovirus Infection

INTRODUCTION

The objective of this study was to investigate myocardial deformation of left (LV) and right ventricle (RV) using 2-dimensional speckle-tracking echocardiography (2D-STE) in fetuses with and without congenital cytomegalovirus (CMV) infection.

METHODS

This was a prospective single-center study. Vertical transmission was defined by a positive CMV polymerase chain reaction (PCR) test on the amniotic fluid or on the neonate's urine. Fetuses were divided into group 1 and group 2 if CMV-PCR was positive or negative, respectively. LV and RV global longitudinal strain (GLS) values were obtained and adjusted for gestational age by calculating Z-scores. Univariate analysis was carried out to compare cardiac indices between group 1 and group 2.

RESULTS

Fetuses from group 1 (n = 11) had a significantly lower LV myocardial shortening than those from group 2 (n = 32). GLS was -20.7 ± 5.2% and -26.3 ± 4.1%, respectively (p = 0.001). Similarly, GLS Z-score was lower (0.02 ± 0.72) in group 1 than in group 2 (-0.80 ± 0.59) (p = 0.001). Similarly, RV GLS Z-score was significantly impaired in group 1 compared to group 2 (-0.44 ± 1.03 vs. -1.04 ± 0.71, p = 0.041).

CONCLUSION

Fetuses with congenital CMV showed subclinical biventricular myocardial dysfunction. Further studies are needed to confirm the potential role of 2D-STE in identifying fetuses with congenital CMV at risk of postnatal cardiovascular morbidities.

The impact of angles of insonation on left and right ventricular global longitudinal strain estimation in fetal speckle tracking echocardiography

OBJECTIVES

Two-dimensional speckle tracking echocardiography has been considered an angle-independent modality. However, current literature is limited and inconclusive on the actual impact of angle of insonation on strain values. Therefore, the primary objective of this study was to assess the impact of angles of insonation on the estimation of fetal left ventricular and right ventricular global longitudinal strain. Secondarily, the impact of different definitions for angles of insonation was investigated in a sensitivity analysis.

METHODS

This is a retrospective analysis of a prospective longitudinal cohort study with 124 healthy subjects. The analyses were based on the four-chamber view ultrasound clips taken between 18+0 and 21+6 weeks of gestation. Angles of insonation were categorized into three groups: up/down, oblique and perpendicular. The mean fetal left and right ventricular and global longitudinal strain values corresponding to these three groups were compared by an ANOVA test corrected for heteroscedasticity.

RESULTS

Fetal left and right ventricular global longitudinal strain values were not statistically different between the three angles of insonation (p-value >0.062 and >0.149, respectively). When applying another definition for angles of insonation in the sensitivity analysis, the mean left ventricular global longitudinal strain value was significantly decreased for the oblique compared to the up/down angle of insonation (p-value 0.041).

CONCLUSIONS

There is no evidence of a difference in fetal left and right ventricular global longitudinal strain between the different angles of insonation in fetal two-dimensional speckle tracking echocardiography.

Longitudinal Behavior of Left-Ventricular Strain in Fetal Growth Restriction

Fetal growth restriction (FGR) is associated with an increased risk of adverse outcomes resulting from adaptive cardiovascular changes in conditions of placental insufficiency, leading to cardiac deformation and dysfunction, which can be evaluated with 2D speckle tracking echocardiography (2D-STE). The aim of the present study was to evaluate whether reduced fetal growth is associated with cardiac left-ventricle (LV) dysfunction, using 2D-STE software widely used in postnatal echocardiography. A prospective longitudinal cohort study was performed, and global (GLO) and segmental LV longitudinal strain was measured offline and compared between FGR and appropriate-for-gestational-age (AGA) fetuses throughout gestation. All cases of FGR fetuses were paired 1:2 to AGA fetuses, and linear mixed model analysis was performed to compare behavior differences between groups throughout pregnancy. Our study shows LV fetal longitudinal strain in FGR and AGA fetuses differed upon diagnosis and behaved differently throughout gestation. FGR fetuses had lower LV strain values, both global and segmental, in comparison to AGA, suggesting subclinical cardiac dysfunction. Our study provides more data regarding fetal cardiac function in cases of placental dysfunction, as well as highlights the potential use of 2D-STE in the follow-up of cardiac function in these fetuses.

Fetal myocardial deformation measured with two-dimensional speckle-tracking echocardiography: longitudinal prospective cohort study of 124 healthy fetuses

OBJECTIVES

Two-dimensional speckle-tracking echocardiography (2D-STE) is a promising technique which allows assessment of fetal cardiac function, and can be used in the evaluation of cardiac and non-cardiac diseases in pregnancy. However, reliable fetal reference values for deformation parameters measured using 2D-STE are needed before it can be introduced into clinical practice. This study aimed to obtain reference values for fetal global longitudinal strain (GLS) and GLS rate (GLSR) measured using 2D-STE and compare right and left ventricular values.

METHODS

This was a prospective longitudinal cohort study of uncomplicated pregnancies that underwent echocardiography every 4 weeks from inclusion at 18-21 weeks until delivery to obtain four-chamber loops of the fetal heart. Left and right ventricular GLS and GLSR were measured using 2D-STE at each examination. Using Bayesian mixed-effects models, reference values with lower and upper 5% prediction limits were calculated according to gestational age. Right and left ventricular GLS values according to gestational age were compared using the Wilcoxon signed-rank test.

RESULTS

A total of 592 left ventricular and 566 right ventricular GLS and GLSR measurements were obtained from 124 women with uncomplicated pregnancy and non-anomalous, appropriately grown fetuses. Reference values were obtained for both fetal ventricles according to gestational week. GLS and GLSR values of both ventricles increased (i.e. became less negative) significantly during pregnancy. Right ventricular GLS values were significantly higher (i.e. less negative) than the respective left ventricular values at every gestational week.

CONCLUSIONS

Reference values were obtained for fetal GLS and GLSR measured using 2D-STE. GLS and GLSR values increased significantly for both ventricles from the second trimester until delivery. GLS values were significantly higher for the right ventricle compared with the left ventricle. Future studies are needed to assess whether the obtained reference values are helpful in clinical practice in the assessment of pregnancy complications, such as fetal growth restriction or cardiac anomaly. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The influence of region of interest width in fetal 2D-speckle tracking echocardiography late in pregnancy

Speckle tracking echocardiography is a promising method for assessment of myocardial function in fetal and neonatal hearts, but further studies are necessary to validate and optimize the settings for use in fetal cardiology. Previous studies have shown that the definition of the region of interest (ROI) affects strain values in adults. The aim of this study was to investigate how different widths of ROI influences measurements of four-chamber longitudinal systolic strain in fetuses late in pregnancy. Thirty-one singleton, healthy fetuses born to healthy mothers underwent an echocardiographic examination during gestational week 37. Speckle tracking was performed with two different settings for ROI width; the narrowest and second most narrow, provided both widths were assessed as suitable for the myocardial wall thickness of the fetus. We found an inverse correlation between the ROI width and the strain values. Four-chamber longitudinal strain changed from - 20.7 ± 3.6% to - 18.0 ± 4.4% (p < 0.001) with increasing ROI width. Further, strain decreased from the endocardium to the epicardium with multilayer measurements. Different widths of ROI influenced the strain measurements significantly in the fetal heart, comparable to what has been reported in adults. A standardization of the ROI setting could improve the interpretation, and reduce variability in fetal strain measurements.

Quantitative evaluation of fetal ventricular function by speckle tracking echocardiography

METHODS

The study included 59 patients with normal fetal heart structure, blood flow, and heart rhythm (fetal abnormality-negative group) and 50 patients with abnormal fetal heart structure, blood flow, and/or heart rhythm (fetal abnormality-positive group). Automated Cardiac Motion Quantification (aCMQ) was performed in both groups to obtain left and right ventricular endocardial global longitudinal strain (GLSendo), mid-myocardial global longitudinal strain (GLSmid), and epicardial global longitudinal strain (GLSepi). Parameters between the two groups were compared and correlation analyses performed. A deformation analysis was performed by two trained observers, and reproducibility was assessed.

RESULTS

The fetal left ventricular and right ventricular global longitudinal strain (LV-GLS and RV-GLS, respectively) decreased in a gradient from the endocardium to the epicardium. LV-GLS and RV-GLS of all myocardial layers were lower in the fetal abnormality-positive than -negative group (all P < 0.05). Correlation analysis showed that neither LV-GLS nor RV-GLS was significantly correlated with gestational age in the fetal abnormality-negative group (all P > 0.05), whereas left ventricular GLSendo, GLSmid, and GLSepi were negatively correlated with gestational age in the fetal abnormality-positive group (r = -.39 to -.44, all P < 0.05). Repeatability testing showed that the inter-observer and intra-observer intra-class correlation coefficients for LV-GLS and RV-GLS in each myocardial layer were >.75 (all P < 0.001).

CONCLUSIONS

As a new speckle tracking echocardiography tool, aCMQ has feasibility and repeatability in evaluating myocardial deformation of the fetal ventricle. This technique might provide helpful information on ventricular myocardial deformation in fetal hearts with abnormal structure or rhythm for clinical guidance in pregnancy.

Speckle tracking derived strain in neonates: planes, layers and drift

The aims of this study was to assess the effect of using a four chamber versus a three plane model on speckle tracking derived global longitudinal strain, the effects of drift compensation, the effect of assessing strain in different layers and finally the interplay between these aspects for the assessment of strain in neonates. Speckle tracking derived longitudinal strain was obtained from 22 healthy neonates. ANOVA, Bland-Altman analyses, coefficients of variation and assessment of intraclass correlation coefficients were conducted to assess the effect of the abovementioned aspects as well as assess both inter-observer and intra-observer variability. Neither the use of the three plane model versus the four chamber model nor the use of drift compensation had a substantial effect on global longitudinal strain (less than 1%, depending on which layer was being assessed). A gradient was seen with increasing strain from the epicardial to endocardial layers, similar to what is seen in older subjects. Finally, drift compensation introduced more discrepancy in segmental strain values compared to global longitudinal strain. Global longitudinal strain in healthy neonates remains reasonably consistent regardless of whether the three plane or four chamber model is used and whether drift compensation is applied. Its value increases when one moves from the endocardial to the epicardial layer. Finally, drift compensation introduces more discrepancy for regional measures of longitudinal strain compared to global longitudinal strain.

Urgent neonatal balloon atrial septostomy in simple transposition of the great arteries: predictive value of fetal cardiac parameters

OBJECTIVES

To investigate the impact of abnormal perinatal loading conditions on cardiac geometry and function in term fetuses and neonates with transposition of the great arteries with intact interventricular septum (simple TGA), and to explore the predictive value of fetal cardiac parameters for an urgent balloon atrial septostomy (BAS) after birth.

METHODS

This was a prospective longitudinal follow-up study of women delivering at term, including both uncomplicated pregnancies with normal outcome and pregnancies affected by fetal simple TGA. Conventional, spectral-tissue Doppler and speckle-tracking echocardiographic parameters were obtained within 1 week before delivery and within the first few hours after delivery. Neonates with simple TGA that required urgent BAS were assessed after the procedure and before corrective arterial switch surgery. Cardiac parameters were normalized by cardiac cycle length, ventricular end-diastolic length or end-diastolic dimension, as appropriate. Fetal and neonatal cardiac parameters were compared between simple-TGA cases and controls, and perinatal changes in the simple-TGA group were assessed. Receiver-operating-characteristics (ROC)-curve analysis was used to assess the predictive value of fetal cardiac parameters for urgent BAS after birth in the simple-TGA group.

RESULTS

A total of 67 pregnant women delivering at term were included in the study (54 normal pregnancies and 13 with a diagnosis of fetal simple TGA). Compared with normal term fetuses, term fetuses with simple TGA exhibited more globular hypertrophied ventricles, increased biventricular systolic function and diastolic dysfunction (right ventricular (RV) sphericity index (SI), 0.58 vs 0.54; left ventricular (LV)-SI, 0.55 vs 0.49; combined cardiac output (CCO), 483 vs 406 mL/min/kg; LV torsion, 4.3 vs 3.0 deg/cm; RV isovolumetric relaxation time (IVRT'), 127 vs 102 ms; P < 0.01 for all). Compared with normal neonates, neonates with simple TGA demonstrated biventricular hypertrophy, a more spherical right ventricle and altered systolic and diastolic functional parameters (RV-SI, 0.61 vs 0.43; RV myocardial performance index, 0.47 vs 0.34; CCO, 697 vs 486 mL/min/kg; LV-IVRT', 100 vs 79 ms; RV-IVRT', 106 vs 71 ms; P < 0.001 for all). Paired comparison of neonatal and fetal cardiac indices in the simple-TGA group showed persistence of the fetal phenotype, increased biventricular systolic myocardial contractility and CCO, and diastolic dysfunction (RV systolic myocardial velocity (S'), 0.31 vs 0.24 cm/s; LV-S', 0.23 vs 0.18 cm/s; CCO, 697 vs 483 mL/min/kg; LV torsion, 1.1 vs 4.3 deg/cm; P < 0.001 for all). Several fetal cardiac parameters in term fetuses with simple TGA demonstrated high predictive value for an urgent BAS procedure after birth. Our proposed novel fetal cardiac index, LV rotation-to-shortening ratio, as a potential marker of subendocardial dysfunction, for a cut-off value of ≥ 0.23, had an area under the ROC curve (AUC) of 0.94, sensitivity of 100% and specificity of 83%. For RV/LV end-diastolic area ratio ≥ 1.33, pulmonary-valve-to-aortic-valve-dimension ratio ≤ 0.89, RV/LV cardiac output ratio ≥ 1.38 and foramen-ovale-dimension-to-total-interatrial-septal-length ratio ≤ 0.27, AUC was 0.93-0.98, sensitivity was 86% and specificity was 83-100% for all.

CONCLUSIONS

Simple-TGA fetuses exhibited cardiac remodeling at term with more profound alterations in these cardiac parameters after birth, suggestive of adaptation to abnormal loading conditions and possible adaptive responses to hypoxemia. Perinatal adaptation in simple TGA might reflect persistence of the abnormal parallel arrangement of cardiovascular circulation and the presence of widely patent fetal shunts imposing volume load on the neonatal heart. The fetal cardiac parameters that showed high predictive value for urgent BAS after birth might reflect the impact of late-gestation pathophysiology and progressive hypoxemia on fetal cardiac geometry and function in simple TGA. If these findings are validated in larger prospective studies, detailed cardiac assessment of fetuses with simple TGA near term could facilitate improvements in perinatal management and refinement of the timing of postnatal intervention strategies to prevent adverse pregnancy outcomes. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of gestational diabetes mellitus on fetal cardiac morphology and function: cohort comparison of second- and third-trimester fetuses

OBJECTIVES

To assess differences in cardiac morphology and function in fetuses of mothers with gestational diabetes mellitus (GDM) compared to controls, and to assess whether, in women with GDM, fetal cardiac changes are accentuated with advancing gestational age.

METHODS

We studied 112 women with GDM and 224 women with uncomplicated pregnancy at 24-40 weeks' gestation. In all fetuses, a standard four-chamber oblique view was obtained and offline speckle-tracking analysis was performed to measure right and left endocardial global longitudinal strain (GLS) and tricuspid and mitral annular plane systolic excursion. Global sphericity index was also calculated. Echocardiographic parameters were compared between GDM fetuses and controls at two gestational time periods of 24 + 0 to 32 + 0 weeks and 32 + 1 to 40 + 1 weeks.

RESULTS

At 24 + 0 to 32 + 0 weeks, we phenotyped 43 fetuses from mothers with GDM and 71 from uncomplicated pregnancies, and, at 32 + 1 to 40 + 1 weeks, we phenotyped 69 fetuses from mothers with GDM and 153 from women with uncomplicated pregnancy. In fetuses of mothers with GDM, compared to controls, right ventricular functional indices were consistently lower both at 24 + 0 to 32 + 0 weeks and at 32 + 1 to 40 + 1 weeks. Right ventricular GLS was reduced in the GDM group at 24 + 0 to 32 + 0 weeks (adjusted mean difference, 0.7%; 95% CI, 0.3-1.1%) and at 32 + 1 to 40 + 1 weeks (adjusted mean difference, 0.9%; 95% CI, 0.6-1.1%). Fetal left ventricular global longitudinal function was similar in GDM pregnancies compared with controls, with the exception of the contractility of the left ventricular basal segment, which was reduced. Global sphericity index was reduced in GDM pregnancies only at 32 + 1 to 40 + 1 weeks (adjusted mean difference, -0.4; 95% CI, -0.7 to 0.1).

CONCLUSIONS

The offspring of women with GDM are at high risk for development of cardiovascular disease in childhood and early adulthood. Our study demonstrates that GDM is associated with a reduction mainly in fetal right ventricular function, compared to controls, and this response is not exaggerated with increasing gestational age. Further studies are needed to determine whether fetuses with the observed alterations in cardiac function are those at highest risk for subsequent development of cardiovascular disease. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Effect of Temporal and Spatial Smoothing on Speckle-Tracking-Derived Strain in Neonates

Clinical application of strain in neonates requires an understanding of which image acquisition and processing parameters affect strain values. Previous studies have examined frame rate, transmitting frequency, and vendor heterogeneity. However, there is a lack of human studies on how user-regulated spatial and temporal smoothing affect strain values in 36 neonates. This study examined nine different combinations of spatial and temporal smoothing on peak systolic left ventricular longitudinal strain in 36 healthy neonates. Strain values were acquired from four-chamber echocardiographic images in the software-defined epicardial, midwall, and endocardial layers in the six standard segments and average four-chamber stain. Strain values were compared using repeated measure ANOVAs. Overall, spatial smoothing had a larger impact than temporal smoothing, and segmental strain values were more sensitive to smoothing settings than average four-chamber strain. Apicoseptal strain decreased by approximately 4% with increasing spatial smoothing, corresponding to a 13-19% proportional change (depending on wall layer). Therefore, we recommend clinicians be mindful of smoothing settings when assessing segmental strain values.

Paired maternal and fetal cardiac functional measurements in women with gestational diabetes mellitus at 35-36 weeks' gestation

BACKGROUND

Gestational diabetes mellitus is associated with early-onset cardiovascular disease and increased incidence of adverse cardiovascular outcomes in mothers and their offspring. Few studies with a limited number of patients have reported subclinical cardiac changes in association with gestational diabetes mellitus; however, it remains unclear whether the mother and the fetus respond in a similar fashion to gestational diabetes mellitus; thus, by assessing the heart of one, we can estimate or predict changes in the other.

OBJECTIVE

This study aimed to compare maternal and fetal cardiovascular functions in the third trimester between women with gestational diabetes mellitus and women with uncomplicated pregnancy and to explore whether gestational diabetes mellitus affects to the same extent the maternal and fetal heart.

STUDY DESIGN

This was a cross-sectional study of maternal and fetal echocardiography for assessment of cardiovascular function in the third trimester in women with singleton pregnancies who received a diagnosis of gestational diabetes mellitus and the control group with uncomplicated pregnancies.

RESULTS

In this study, we included 161 women with gestational diabetes mellitus and 483 women with uncomplicated pregnancies. Compared with women in the control group, women with gestational diabetes mellitus were older (34.5, standard deviation, 5.3 years] vs 32.5, standard deviation, 4.8 years]; P<.001), had higher body mass index (31.3 kg/m² [standard deviation, 5.8] vs 28.6 kg/m² [standard deviation, 4.4]; P<.001), had lower weight gain during pregnancy (8.3 [interquartile range, 4.8-11 kg] vs 10.8 [interquartile range, 8.2-13.5 kg]; P<.001), and delivered babies with lower birthweight (P<.001). After multivariable analysis, accounting for differences in maternal characteristics and fetal weight, mothers with gestational diabetes mellitus had lower left ventricular diastolic and systolic (tissue Doppler systolic [s'] wave) functional indices (P<.01 for both) compared with those of mothers in the control group. The noted cardiac changes did not fulfill the adult criteria for clinical cardiac dysfunction. No differences in hemodynamic indices (cardiac output and peripheral vascular resistance) and left ventricular mass were noted between the groups. Fetuses of mothers with gestational diabetes mellitus had more globular-shaped hearts with increased right and left ventricular sphericity indices (P<.001 for both) and reduced global longitudinal right and left ventricular systolic functional indices (P<.001 for both). The effect of gestational diabetes mellitus on maternal and fetal hearts was different, and there was no clear association between the two.

CONCLUSION

In the third trimester, in pregnancies with gestational diabetes mellitus, there were subclinical cardiac changes in both the mother and the fetus, but there was no significant difference in any of the fetal cardiac parameters between women with and women without unfavorable cardiac profile. This suggests that the stimulus for cardiovascular responses in the mother and fetus may not be the same in pregnancies with gestational diabetes mellitus.

Two-dimensional Speckle tracking echocardiography in Fetal Growth Restriction: a systematic review

Background Fetal growth restriction (FGR), defined as an estimated fetal weight (EFW)<10th percentile, is associated with an increased risk for adverse fetal and neonatal outcome. Early antenatal diagnosis is important and remains challenging. Deformation changes in the fetal myocardium are early signs of myocardial dysfunction. These changes can be measured using two-dimensional speckle tracking echocardiography (2D-STE) to predict impaired placental function in the growth restricted fetus. Aim To review the literature on fetal heart deformation values measured with 2D-STE, in fetuses with an EFW< 10th centile and appropriate for gestational age (AGA) fetuses, and to compare the results in both groups. Methods The EMBASE, Medline, and Cochrane databases were searched from inception until April 2020. Observational studies on evaluating the cardiac deformation values longitudinal strain, strain rate, and/or global dyssynchrony of both ventricles in FGR, using 2D-STE, were included. Methodological quality was assessed using the Newcastle-Ottowa risk of bias scale. Results Four studies met the inclusion criteria. The mean gestational age (GA) varied from 30 to 38 weeks in the FGR group and 20 to 40 weeks in AGA fetuses. The number of included FGR fetuses (with or without Doppler abnormalities), varied from 30 to 50. Longitudinal strain in FGR fetuses was described as comparable (n = 2), increased (n = 1) and>95th percentile (n = 1) compared to AGA fetuses. Strain rate was measured in two studies. One reported an increased strain rate, another showed comparable strain rate. Two studies addressed global left ventricle (LV) and right ventricle (RV) dyssynchrony. Dyssynchrony was increased in FGR compared to AGA fetuses. Conclusion The currently published data is limited and heterogeneous concerning GA and Doppler profiles. The data presentation and the interpretation thereof make qualitative comparisons impossible. Large prospective longitudinal cohort studies looking at the value of deformation measurements of the fetal heart in FGR and AGA fetuses are needed to assess the clinical significance of deformation values measured with 2D-STE.

Cardiac function in gestational diabetes mellitus: A longitudinal study from fetal life to infancy

OBJECTIVE

To determine whether cardiac functional and structural changes in fetuses of mothers with gestational diabetes mellitus (GDM) persist in the offspring beyond the neonatal period.

DESIGN

Longitudinal study.

SETTING

Fetal Medicine Unit in a UK teaching hospital.

METHODS

73 women with GDM and 73 women with uncomplicated pregnancy were recruited and fetal cardiac scans were performed at 35-36 weeks' gestation. Repeat echocardiogram was performed in their offspring during infancy.

MAIN OUTCOME MEASURES

Fetal and infant cardiac functional and structural changes.

RESULTS

Fetuses of mothers with GDM, compared with controls, had more globular right ventricles (sphericity index 0.7, interquartile range [IQR] 0.6/0.7 versus 0.6, IQR 0.5/0.6, P < 0.001) and reduced right global longitudinal systolic strain (-16.4, IQR -18.9/-15.3 versus -18.5, IQR -20.6/-16.8, P = 0.001) and left global longitudinal systolic strain (-20.1, IQR -22.5/-16.9 versus -21.3, IQR -23.5/-19.5), P = 0.021). In the GDM group, compared with controls, in infancy there was higher left ventricular E/e' (8.7, IQR 7.3/9.7 versus 7.9 IQR, 6.8/8.9 P = 0.011) and lower left ventricular global longitudinal systolic strain (-21.0, IQR -22.5/-19.4 versus -22.3, IQR -23.5/-20.7, P = 0.001) and tricuspid annular plane systolic excursion (13.8, IQR 12.7/16.1 versus 15.2, IQR 13.8/16.8, P = 0.003). These differences remained following multivariable analysis.

CONCLUSION

Gestational diabetes mellitus is associated with alterations in fetal cardiac function and structure compared with controls and persistent cardiac changes in infancy.

TWEETABLE ABSTRACT

Gestational diabetes mellitus, even when well controlled, is associated with fetal cardiac changes and these persist in infancy.

Fetal Speckle-Tracking: Impact of Angle of Insonation and Frame Rate on Global Longitudinal Strain

BACKGROUND

There is a growing body of research on fetal speckle-tracking echocardiography because it is considered to be an angle-independent modality. The primary aim of this study was to investigate whether angle of insonation and acquisition frame rate (FR) influence left ventricular endocardial global longitudinal peak strain (GLS) in the fetus.

METHODS

Four-chamber views of 122 healthy fetuses were studied at three different angles of insonation (apex up/down, apex oblique, and apex perpendicular) at high and low acoustic FRs. GLS was calculated, and a linear mixed-model analysis was used for analysis. Six hundred fifty-six fetal echocardiographic clips were analyzed (288 in the second trimester, at a median gestation of 21 weeks [interquartile range (IQR), 1 week], and 368 in the third trimester, at a median gestation of 36 weeks [IQR, 2 weeks]).

RESULTS

Angle of insonation and FRs were significant determinants of GLS. Ventricular septum perpendicular to the ultrasound beam was associated with higher (more negative) GLS compared with apex up/down (at high FR: -21.8% vs -19.7%, P < .001; at low FR: -24.1% vs -21.4%, P < .001). Higher frames per second (FPS; median 149 FPS [IQR, 33 FPS] = 61 frames per cycle [FPC] [IQR, 17 FPC]) compared with lower FPS (median 51 FPS [IQR, 15 FPS] = 22 FPC [IQR, 7 FPC]) at the same insonation angle resulted in lower GLS (apex up/down: -19.7% vs -21.4%, P < .001; apex oblique: -21.2% vs -22.7%, P < .001; apex perpendicular: -21.8% vs -24.1%, P < .001).

CONCLUSIONS

The present findings show that insonation angle and FR influence GLS significantly. These factors need to be considered when comparing studies with different acquisition protocols, when establishing normative values, and when interpreting pathology. Speckle-tracking echocardiography cannot be considered an angle-independent modality during fetal life.

Fetal strain and strain rate during pregnancy measured with speckle tracking echocardiography: A systematic review

Establishment of the maturational patterns of the fetal left and right ventricle strain and strain rate by two-dimensional speckle tracking echocardiography is a prerequisite for its routine clinical adaptation in pregnancy. The aim of this study is to review systematically current literature on the development of left and right ventricle strain and strain rate derived by speckle tracking during gestation. EMBASE, Medline and Central were searched, from inception to October 2019, for observational studies of singletons in uncomplicated, non-anomalous pregnancies, measuring global longitudinal strain and strain rate with 2D speckle tracking echocardiography in the fetal heart during gestation. 23 Studies met the inclusion criteria. The gestational age of the included fetuses varied from 12 to 42 weeks. Four studies used a longitudinal study design, with few consecutive measurements at varying gestational ages. 19 Studies performed either cross sectional or both longitudinal and cross sectional measurements. The ultrasound devices and speckle tracking algorithm software used, varied. Strain and strain rate during gestation increased, decreased or remained stable in the left and right fetal ventricle with increasing gestation. Due to considerable variation in the included gestational ages measured and inconsistency in the direction of strain and strain rate development, a meta-analysis could not be performed. Contradictory results concerning the development of strain and strain rate during gestation were shown, probably due to suboptimal study designs and varying algorithms and ultrasound devices used. A large longitudinal cohort study is needed to obtain reference values for fetal cardiac deformation in the uncomplicated, singleton pregnancy.