Evaluation and Management of Fetal Cardiac Function and Heart Failure

Care of the Fetus With Congenital Cardiovascular Disease: From Diagnosis to Delivery

BACKGROUND

The majority of congenital cardiovascular disease including structural cardiac defects, abnormalities in cardiac function, and rhythm disturbances can be identified prenatally using screening obstetrical ultrasound with referral for fetal echocardiogram when indicated.

METHODS

Diagnosis of congenital heart disease in the fetus should prompt assessment for extracardiac abnormalities and associated genetic abnormalities once maternal consent is obtained. Pediatric cardiologists, in conjunction with maternal-fetal medicine, neonatology, and cardiothoracic surgery subspecialists, should counsel families about the details of the congenital heart defect as well as prenatal and postnatal management.

RESULTS

Prenatal diagnosis often leads to increased maternal depression and anxiety; however, it decreases morbidity and mortality for many congenital heart defects by allowing clinicians the opportunity to optimize prenatal care and plan delivery based on the specific lesion. Changes in prenatal care can include more frequent assessments through the remainder of the pregnancy, maternal medication administration, or, in selected cases, in utero cardiac catheter intervention or surgical procedures to optimize postnatal outcomes. Delivery planning may include changing the location, timing or mode of delivery to ensure that the neonate is delivered in the most appropriate hospital setting with the required level of hospital staff for immediate postnatal stabilization.

CONCLUSIONS

Based on the specific congenital heart defect, prenatal echocardiogram assessment in late gestation can often aid in predicting the severity of postnatal instability and guide the medical or interventional level of care needed for immediate postnatal intervention to optimize the transition to postnatal circulation.

The Diagnostic Yield of Fetal Echocardiography Indications in the Current Era

BACKGROUND

The aim of this study was to examine the diagnostic yield of current fetal echocardiography (FE) indications representing a recent era.

METHODS

FE reports of all pregnancies referred to two provincial FE programs from 2009 to 2018 were examined, identifying the indication for FE (14 categories), gestational age at referral, and whether there was no fetal heart disease (FHD), mild or possible FHD (e.g., simple ventricular septal defect, possible coarctation), or moderate or severe FHD.

RESULTS

Over the study period, there were 19,310 unique FE referrals in Alberta (23.3 ± 5.4 weeks' gestation), including 1,907 (9.9%) with moderate or severe and 654 (3.4%) with mild or possible FHD. The most common referral indications included extracardiac pathology or markers (29.7%), maternal diabetes (18.3%), suspected FHD (17.7%), and family history of heart defects (17.7%). The highest yield for moderate or severe FHD was suspected FHD (41.1%; 95% CI, 39.4%-42.7%), followed by suspected or confirmed genetic disorder (15.4%; 95% CI, 12.6%-18.2%), twins or multiples (10.6%; 95% CI, 8.7%-12.5%), oligohydramnios (8.0%; 95% CI, 4.1%-11.9%), extracardiac pathology or markers (6.4%; 95% CI, 5.8%-7.1%), and heart not well seen (5.8%; 95% CI, 4.0%-7.6%). Lowest yields were observed for maternal diabetes (2.2%; 95% CI, 1.7%-2.7%) and family history of heart defects (1.7%; 95% CI, 1.3%-2.2%). Excluding suspected FHD, with two or more FE indications, all other indications demonstrated significant increases in yield of mild or possible (3.5% vs 1.9%, P < .001) and moderate or severe (7.2% vs 2.9%, P < .001) FHD.

CONCLUSIONS

Suspected FHD provides the highest diagnostic yield of moderate or severe FHD. In contrast, maternal diabetes and family history of heart defects, among the most common referral indications, had diagnostic yields approaching general population risks. Even in the absence of suspected FHD, having two or more referral indications importantly increases the diagnostic yield of all other FE indications.

Foetal cardiac function in third trimester pregnancies with reduced fetal movements

The objective of our study was to investigate the possible relationship between poor perinatal outcome and foetal cardiac functions in pregnant women with reduced foetal movements (RFM). This cross-sectional study included 126 pregnant women with normal foetal movements (Group 1, Controls) and 42 pregnant women over 32 weeks gestation with RFM (Group 2). Group 2 was further divided into two subgroups according to their perinatal outcome: normal perinatal outcome (Group 2a) and poor perinatal outcome (Group 2b). Cardiotocography, the E/A ratio in both atrioventricular valves, myocardial performance index (MPI) and foetal tricuspid annular plane systolic excursion (f-TAPSE) were evaluated. Foetuses with poor perinatal outcome had a higher MPI (p = .003), higher tricuspid and mitral E/A (p < .001), and lower f-TAPSE values (p < .001). In regression analysis, f-TAPSE was the only parameter (p = .04) independently associated with poor perinatal outcome. İn conclusion, examining f-TAPSE may predict adverse perinatal outcome in pregnancies with RFM.IMPACT STATEMENTWhat is already known on this subject? Reduced foetal movement (RFM) is associated with adverse pregnancy outcome. Cardiotocography, amniotic fluid assessment, estimated birthweight, foetal Doppler and formal foetal movement count (kick chart) are generally used in the clinical assessment of pregnancies with reduced foetal movements. These tests, we currently use to assess foetal wellbeing in women with reduced foetal movements, have limited sensitivity in predicting foetal compromise.What do the results of this study add? Foetal cardiac Doppler may potentially be used as an important adjunct to the conventional management of women with a perception of reduced foetal movements.What are the implications of these findings for clinical practice and/or further research? Foetal echocardiographic evaluation, such as f-TAPSE, may influence clinical practice by enabling improved risk stratification for poor perinatal outcome, thus allowing more timely definitive intervention. This could help to decrease the rate of stillbirth related to reduced foetal movements. The few established echocardiographically derived parameters, which can asses global right ventricle function, are not always easy to obtain, however, f-TAPSE is easily obtainable using ultrasound and it appears to be a clinically useful echocardiographic measurement of right ventricular function.

Annular plane systolic excursion Z-scores in evaluation of heart systolic function of fetus with heart failure

OBJECTIVE

To compare fetal tricuspid annular plane systolic excursion(TAPSE）Z-scores and mitral annular plane systolic excursion(MAPSE) Z-scores between fetuses with heart failure (HF) and normal fetuses, and to analysis the correlation between CVPS and annular plane systolic excursion(APSE) Z-score(sum of the TAPSE and MAPSE Z-score) in order to evaluate the ventricle systolic function and severity in fetuses with HF.

METHODS

A total of 1012 normal fetuses and 24 fetuses with heart failure were involved. TAPSE and MAPSE were measured by free angle M-mode(FAM) echocardiography. Normal FAM-TAPSE and FAM-MAPSE Z-score models based on GA were constructed by performing a standard regression analysis followed by weighted regression of absolute residual values . Tei indexes were calculated in all fetuses with heart failure and all of them were divided into left heart failure (LHF)group and right heart failure（RHF)group by Tei index. Subsequently, FAM-MAPSE Z-scores were compared between the normal and LHF groups, FAM-TAPSE Z-scores were compared between the normal and RHF groups．FAM-APSE Z-scores (sum of the FAM-TAPSE and FAM-MAPSE Z-score) and the cardiovascular profile scores (CVPS) in 24 fetuses were calculated, the correlation was analyzed among them.

RESULTS

The models used to calculate Z-score for FAM-TAPSE and FAM-MAPSE were constructed, and GA had significant correlation with them (r = 0.949, p < 0.001for all)．Compared with normal fetuses, the mean Z-scores of FAM-TAPSE and FAM-MAPSE were statistically significantly different in fetuses with HF．In the HF groups, all FAM-TAPSE and FAM-MAPSE Z-scores(22/22) were <-2. CVPS ranged from 3 to 8 (mean 5.25 out of 10) and correlated positively with FAM-APSE Z-score (r = 0.762).

CONCLUSIONS

The FAM-TAPSE and FAM-MAPSE Z-scores declined in fetuses with HF and they can provide quantitative evidence in evaluation of heart systolic function, FAM-APSE Z-score correlated positively with CVPS. FAM-TAPSE, FAM-MAPSE and FAM-APSE Z-scores would be markers for assessing heart systolic function and severity in fetuses with HF.

Longitudinal assessment of ventricular strain, tricuspid and mitral annular plane systolic excursion (TAPSE and MAPSE) in fetuses from pregnancies complicated by diabetes mellitus

OBJECTIVES

To evaluate fetal cardiac function using myocardial deformation analyses, tricuspid annular plane systolic excursion (TAPSE), mitral annular plane systolic excursion (MAPSE) and diastolic function parameters in pregnancies complicated by maternal diabetes mellitus.

METHODS

Myocardial deformation using velocity vector imaging (VVI), TAPSE, MAPSE and diastolic function was measured in 126 women with uncomplicated singleton pregnancies and 50 women with diabetes mellitus. Women underwent ultrasound scans every four weeks from recruitment (18-28 weeks gestational age) until delivery.

RESULTS

Left ventricle strain and strain rate, right ventricle strain and strain rate, TAPSE, MAPSE and diastolic parameters were not different between the diabetic cohort and controls throughout gestation. We did not find any significant correlation between the fetal cardiac function parameters with parity or smoking status. There was however a significant difference in strain and strain rate values in the left ventricle, but not the right ventricle in women with BMI >30 kg/m², and reduced TAPSE values in this same group. Fetuses in the diabetes group had thicker interventricular septum (IVS) throughout gestation.

CONCLUSION

Myocardial deformation of the fetal left ventricle, as measured by VVI, and TAPSE were reduced in fetuses of mothers in association with maternal obesity but not in women with diabetes mellitus. No significant differences in the fetal cardiac function parameters measured were different between the two groups, except for IVS thickness.

Evolution of strain and strain rate values throughout gestation in healthy fetuses

Myocardial deformation by speckle tracking echocardiography is a novel method for evaluating cardiac function. To test the hypothesis that right ventricular and left ventricular function have age-specific patterns of development, we tracked the evolution of ventricular strain mechanics by speckle tracking echocardiography in the fetus. We conducted a retrospective cross sectional echocardiography study in 154 healthy fetuses, and characterized cardiac function by measuring right and left ventricles global longitudinal strain and strain rate. Comparison of the data of both ventricles according to gestational age was carried out. The magnitudes of right and left ventricle global longitudinal strain show wide range values and decreased throughout gestation. Strain values are higher in left ventricle compared to the right one throughout pregnancy. Strain rate values were similar over gestation in each ventricle, but the magnitudes declined overtime in the right and left ventricle. The maturational patterns of left and right strain are gestational specific. With accepted physiological maturation patterns in healthy subjects, these myocardial deformation parameters can provide a valid basis that allows comparison between health and disease.

Assessment of fetal cardiac function with echocardiography

The circulatory physiology of fetuses differs from that of neonates. The concept of biventricular combined cardiac output is necessary to understand and assess the fetal cardiac function. Fetal cardiac function has been estimated using echocardiographic methods such as M-mode, B-mode and pulsed wave Doppler. In addition, recent studies have reported the utility of tissue Doppler imaging in fetal echocardiography. However, parameters for fetal cardiac function remain to be established. Recently, we developed two novel techniques for assessing fetal cardiac function: an automatic fractional shortening method and E/e' determination using the dual-gate Doppler method. These two techniques are expected to be reliable and useful for assessing the fetal status in various pathological conditions.

Feasibility of automated fetal fractional shortening measurement with two-dimensional tracking and construction of a reference range for normal fetuses

PURPOSE

To assess the feasibility of an automated fractional shortening (Auto FS) measurement method using two-dimensional tracking and to construct a reference range for normal fetuses.

METHODS

This study was conducted from May 2017 to March 2018. First, cardiac motion in the four-chamber view was recorded in the B-mode. Subsequently, the region of interest was set on the edge of the ventricular septum or ventricular muscle at a point one-third away from the atrioventricular valve toward the cardiac apex. Tracking was automatically performed. Values measured between the ventricular septum and right ventricle were defined as R-Auto FS, whereas those measured between the ventricular septum and left ventricle were defined as L-Auto FS. Those on each ventricular muscle were defined as Combined-Auto FS.

RESULTS

Data were obtained from 131 singleton fetuses. R-Auto FS significantly decreased with an increase in the number of gestational weeks, and L-Auto FS and Combined-Auto FS showed the same tendency (Spearman's correlation analysis: p = - .528, p = - .351, and p = - .636, respectively).

CONCLUSION

We succeeded in defining a reference Auto FS value for normal singleton pregnancies. Auto FS was negatively correlated with gestational age. This novel technique can assess fetal heart contractility.

Fetal Cardiac Doppler Signal Processing Techniques: Challenges and Future Research Directions

The fetal Doppler Ultrasound (DUS) is commonly used for monitoring fetal heart rate and can also be used for identifying the event timings of fetal cardiac valve motions. In early-stage fetuses, the detected Doppler signal suffers from noise and signal loss due to the fetal movements and changing fetal location during the measurement procedure. The fetal cardiac intervals, which can be estimated by measuring the fetal cardiac event timings, are the most important markers of fetal development and well-being. To advance DUS-based fetal monitoring methods, several powerful and well-advanced signal processing and machine learning methods have recently been developed. This review provides an overview of the existing techniques used in fetal cardiac activity monitoring and a comprehensive survey on fetal cardiac Doppler signal processing frameworks. The review is structured with a focus on their shortcomings and advantages, which helps in understanding fetal Doppler cardiogram signal processing methods and the related Doppler signal analysis procedures by providing valuable clinical information. Finally, a set of recommendations are suggested for future research directions and the use of fetal cardiac Doppler signal analysis, processing, and modeling to address the underlying challenges.

Fetal isovolumetric time intervals as a marker of abnormal cardiac function in fetal anemia from homozygous alpha thalassemia-1 disease

OBJECTIVE

To determine whether fetal isovolumetric time intervals can be an early sonographic marker of fetal anemia in fetuses with homozygous alpha thalassemia-1.

METHODS

Pregnancies at risk for fetal homozygous alpha thalassemia-1 disease at 18-22 weeks were recruited before cordocentesis for hemoglobin typing. Isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) intervals were measured by placing pulsed wave Doppler sample volume within the left ventricle to obtain the mitral and aortic waveform. Time intervals were compared between the affected group of homozygous alpha thalassemia-1 fetuses and the unaffected group.

RESULTS

Among 70 fetuses at risk, 28 cases were diagnosed as affected by homozygous alpha thalassemia-1 disease. Mean ICT and ICT + IRT intervals in the affected group were significantly longer than in the unaffected group (47.9 ± 12.5 ms vs 35.0 ± 6.7 ms, p < 0.001; and 96.2 ± 13.6 ms vs 80.9 ± 10.6 ms, p < 0.001. ICT effectively predicted affected fetuses with 71.4% sensitivity and 78.6% specificity using a cutoff value ≥40 ms.

CONCLUSIONS

Isovolumetric contraction time was significantly prolonged in fetal anemia from homozygous alpha thalassemia-1 during the early stage of hydropic changes. Because of its simple measurement and high efficacy, ICT can be a useful marker for prenatal screening of abnormal cardiac function in fetal anemia. © 2017 John Wiley & Sons, Ltd.