Quantitative Assessment of Cardiac Function in Fetuses of Women with Maternal Gestational Thyroid Dysfunction Using VVI Echocardiography

To investigate the correlation between normal fetal biventricular myocardial function and gestational age using velocity vector imaging

Objective

The aim of this study was to evaluate the left and right ventricular segmental and global myocardial function of normal fetuses using velocity vector imaging and explore the correlation between global myocardial function parameters and gestational age.

Methods

A total of 127 normal fetuses were selected and divided into five groups according to gestational age for the measurement of their left and right ventricular segmental and global velocity, strain, and strain rate. This study also explored the change trend in the global myocardial function parameters at different gestational ages and analyzed its correlation with gestational age.

Results

The peak velocities of the biventricular segments of the normal fetuses showed a decreasing trend from the basal to the middle to the apex segment, and the differences were statistically significant (P < 0.05). However, the strain and peak strain rate between adjacent segments showed no significant differences (P > 0.05). The peak global velocity of both ventricles increased with the gestational age, and it was moderately correlated with gestational age; however, the correlation of strain and peak strain rate with gestational age was not statistically significant (P > 0.05).

Conclusion

In normal fetuses, the peak myocardial velocity of the biventricular segments showed a decreasing trend from the basal to the apical segment. The global peak myocardial velocity was linearly correlated with gestational age; however, the global strain and peak strain rate did not change as gestational age increased, indicating that the myocardial deformability of the fetus' ventricles was constant in the middle and late trimesters.

The assessment of fetal cardiac output in maternal hypothyroidism under levothyroxine treatment

OBJECTIVE

In this study, we investigated whether maternal hypothyroidism has a role in the cardiac output (CO) of the fetus or not.

METHODS

Pregnant women between 33 and 37 gestational weeks known to have hypothyroidism and using levothyroxine were accepted as the case group. Gestational age-matched healthy euthyroid pregnant women constituted the control group. Fetal echocardiography was performed. Diameters and the velocity waveform of the pulmonary artery (PA) and aortic valves were measured. Velocity time integral (VTI) was also measured from the ventricular outflow tract. CO was calculated using VTI × π (Aortic Valve or Pulmonary Valve diameter/2) 2 × heart rate formula.

RESULTS

The aortic and PA annulus were measured larger in the control group. (p = .003, p = .005, respectively). Furthermore, the right and left CO of the case group were lower than the control group. Whereas the mean combined CO (ml/min) of the case group was 674.8 ± 146.2, it was 827.8 ± 167.9 in the control group (p < .001). Additionally, a negative correlation was observed between thyroid-stimulating hormone and aortic VTI (r:-.480; p:.006).

CONCLUSION

The findings of our study suggest that the CO of the fetus may be affected by maternal hypothyroidism.

Evaluation of biventricular longitudinal myocardial function in normal fetuses at different gestational ages using ultrasonic velocity vector imaging

Objective

This study aimed to evaluate biventricular myocardial function and biventricular longitudinal global myocardial function of fetuses at different gestational weeks using ultrasonic velocity vector imaging.

Methods

A total of 127 pregnant women were enrolled and divided into five groups according to the gestational age of their fetuses. The velocity, strain, and strain rate of the left and right ventricles were measured, and these biventricular parameters were compared between the groups. The global parameters of the biventricular myocardium were also compared.

Results

A pairwise comparison revealed that the differences in biventricular velocity and strain rate between groups in adjacent gestational weeks were not statistically significant (P > 0.05), but velocity increased with gestational age. A comparison of fetal longitudinal global myocardial parameters revealed that the global velocity, strain, and strain rate of the right ventricle were higher than those of the left ventricle, and the differences were statistically significant (P < 0.05) in all groups.

Conclusion

The peak velocities of the fetal left and right ventricles increased with gestational age, but the global strain and strain rate did not, suggesting that fetal myocardial function is mature and constant in the middle and late stages of pregnancy and can more reliably reflect myocardial deformation. The peak systolic velocity, global strain, and peak strain rate of the right ventricle were higher than those of the left ventricle, suggesting that the right ventricle dominates longitudinal systolic movement from the second trimester of pregnancy.

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.

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.

Evaluation of left ventricular myocardial movement in rats by velocity vector imaging

AIM

To use velocity vector imaging (VVI) technology to evaluate the correlation between the apical four-chamber view and short-axis myocardial movement in rats.

METHODS

We used 25 10-week-old male Sprague-Dawley rats to measure the myocardium peak systolic velocity (Vs; cm/s), peak diastolic velocity (Vd; cm/s), peak systolic strain (SR; %), peak systolic strain rate (SRs; 1/s), and peak diastolic strain rate (SRd; 1/s) from the apical four-chamber view of the left ventricle (LV) and the parasternal mitral valve (PMV)-level short-axis view, and to analyze the correlation between myocardial motion in corresponding views of the two sections.

RESULTS

Comparing the myocardial motion between the lateral wall's basal segment in the apical four-chamber view of the LV and the lateral wall of the PMV-level short-axis view revealed that the Vd was positively correlated (r = 0.59, p<0.01), as was SRs (r = 0.68, p<0.05). Comparing the myocardial motion between the lateral wall's middle segment in the apical four-chamber view of the LV and the lateral wall of the PMV-level short-axis view demonstrated that Vd, SRs, and SRd were positively correlated (r = 0.63, 0.82, 0.79, respectively, all p<0.01). Our comparison of myocardial motion between the posterior septum's basal segment in the apical four-chamber view of the LV and the posterior septum of PMV-level short-axis view showed that Vd and SRs were positively correlated (r = 0.57, 0.68, respectively, both p<0.01). Comparing the myocardial motion between the posterior septum's middle segment in the apical four-chamber view of the LV and the posterior septum of the PMV-level short-axis view revealed that Vs, Vd, SR, and SRd were positively correlated (r = 0.89, 0.63, 0.64, 0.6, respectively, all p<0.01), and the SRs also had a significant positive correlation (r = 0.53, p<0.05).

CONCLUSION

VVI technology could be a valuable tool for evaluating the myocardial walls motion of the apical four-chamber view of the rat LV.

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.

Velocity vector imaging echocardiography and NT-proBNP study of fetal cardiac function in pregnancy-induced maternal hypertension

PURPOSE

To investigate whether acute and transient pressure overload in patients with pregnancy-induced hypertension affects cardiac function in fetuses.

METHODS

We enrolled 104 singleton pregnant women with gestational ages ranging 30 to 33 weeks, visiting for prenatal care. Among them, 34 had gestational hypertension (GH), 32 had preeclampsia (PE), and 38 were healthy and formed the control group. Conventional echocardiographic and velocity vector imaging (VVI) variables were prospectively collected. Blood levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured from cord blood drawn at birth.

RESULTS

The fetuses of mothers with preeclampsia had significantly lower left (LV) and right ventricle (RV) diastolic strain rate (SRd) and RV strain (S) and systolic strain rate (SRs) than controls. LV and RV S, SRd, and SRS were not different in fetuses of mothers with GH and controls. The NT-proBNP levels were higher in fetuses of patients with PE than in GH and controls.

CONCLUSIONS

In the third trimester of pregnancy, fetal biventricular function and NT-proBNP levels are not significantly influenced by GH. Fetuses of mothers with PE present signs of LV and RV diastolic dysfunction, right ventricular systolic dysfunction, and elevated NT-pro-BNP levels. VVI echocardiography appears more sensitive than conventional echocardiography to evaluate fetal cardiac function.

Assessment of strain and dyssynchrony in normal fetuses using speckle tracking echocardiography - comparison of three different ultrasound probes

OBJECTIVE

To evaluate segmental left (LV-S) and right (RV-S) ventricular strain as well as longitudinal mechanical myocardial dyssynchrony as a time difference between peaks in strain of both ventricles in fetuses (two-chamber-dyssynchrony, 2C-DYS) using speckle tracking echocardiography (STE). The aim of our study was to evaluate the influence of data acquisition on the results of STE measurement using different ultrasound probes.

METHODS

We prospectively recorded cardiac cycles of four-chamber views of 56 normal fetuses with three different ultrasound probes and analyzed them offline with speckle tracking imaging software. Furthermore, we looked at a possible influence of heartbeat variability (beat-to-beat variability).

RESULTS

The evaluation of the parameters was feasible with all three probes in 53 cases. There was no influence of heartbeat variability and no noticeable differences in 2C-DYS, LV-S and RV-S in all cases and for all three probes determined.

CONCLUSION

Assessment of strain and dyssynchrony using STE with three different probes is comparable. Further research is needed to validate dyssynchrony as a predictor for fetal outcome.

Left ventricular function of patients with pregnancy-induced hypertension evaluated using velocity vector imaging echocardiography and N-terminal pro-brain natriuretic peptide

PURPOSE

To investigate whether acute and transient pressure overload in patients with pregnancy-induced hypertension (PIH) affects left ventricular (LV) systolic function.

METHODS

From pregnancy to 3 months after delivery, 82 patients were analyzed: 27, 25, and 30 with gestational hypertension, preeclampsia, and the healthy control group, respectively. Conventional echocardiography and velocity vector imaging (VVI) were performed, and blood levels of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) were analyzed.

RESULTS

Compared with the control group, patients with gestational hypertension had significantly lower mean LV peak global longitudinal strain. Importantly, during both pregnancy and after delivery, patients with preeclampsia had significantly lower global longitudinal, circumferential, and radial strain compared with the control group. The NT-pro-BNP levels were significantly higher in patients with PIH compared with normotensive pregnancies, and this situation continued for 3 months after delivery in women with preeclampsia.

CONCLUSIONS

In pregnancies complicated by pregnancy-induced hypertension, especially preeclampsia, the systolic function is impaired and NT-pro-BNP levels are elevated compared with normal pregnancy. Velocity vector imaging (VVI) is more sensitive than left ventricular ejection fraction to evaluate heart function in patients with PIH.

Assessment of Fetal Myocardial Performance Index in Women with Placenta Previa

Background

This study investigated whether fetuses of placenta previa pregnancies have cardiac dysfunction by use of a modified myocardial performance index (Mod-MPI).

Material/Methods

A prospective cross-sectional study was conducted including 178 fetuses at 28–40 weeks of gestation. Eighty-nine fetuses of mothers with placenta previa and without pregnancy complications were recruited (placenta previa group) and matched with 89 fetuses of mothers with normal pregnancies (control group). Fetal cardiac function parameters and perinatal outcomes as well as the Mod-MPI were compared between the 2 groups.

Results

The median Mod-MPI was significantly increased in fetuses of mothers with placenta previa compared with controls (0.47±0.05 vs. 0.45±0.05; P<0.01). Among fetuses of mothers with or without placenta previa, the Mod-MPI was significantly higher in the incomplete placenta previa group compared with the complete placenta previa group and control group (P<0.01). An increased Mod-MPI in placenta previa pregnancies was independently associated with fetal cord pH <7.2 (odds ratio, 4.8; 95% confidence interval, 0.98–23.54; P=0.003).

Conclusions

There is impairment of fetal cardiac function in pregnancies with placenta previa. An increased MPI was independently associated with adverse perinatal outcomes to some extent in the placenta previa pregnancies.