Cardiac hemodynamics in fetuses with transposition of the great arteries and intact ventricular septum from diagnosis to end of pregnancy: longitudinal follow-up

D-Transposition of the great arteries with restrictive foramen ovale in the fetus: the dilemma of predicting the need for postnatal urgent balloon atrial septostomy

OBJECTIVE

Restrictive foramen ovale (FO) in dextro-transposition of the great arteries (d-TGA) with intact ventricular septum may lead to severe life-threatening hypoxia within the first hours of life, making urgent balloon atrial septostomy (BAS) inevitable. Reliable prenatal prediction of restrictive FO is crucial in these cases. However, current prenatal echocardiographic markers show low predictive value, and prenatal prediction often fails with fatal consequences for a subset of newborns. In this study, we described our experience and aimed to identify reliable predictive markers for BAS.

METHODS

We included 45 fetuses with isolated d-TGA that were diagnosed and delivered between 2010 and 2022 in two large German tertiary referral centers. Inclusion criteria were the availability of former prenatal ultrasound reports, of stored echocardiographic videos and still images, which had to be obtained within the last 14 days prior to delivery and that were of sufficient quality for retrospective re-analysis. Cardiac parameters were retrospectively assessed and their predictive value was evaluated.

RESULTS

Among the 45 included fetuses with d-TGA, 22 neonates had restrictive FO postnatally and required urgent BAS within the first 24 h of life. In contrast, 23 neonates had normal FO anatomy, but 4 of them unexpectedly showed inadequate interatrial mixing despite their normal FO anatomy, rapidly developed hypoxia and also required urgent BAS ('bad mixer'). Overall, 26 (58%) neonates required urgent BAS, whereas 19 (42%) achieved good O2 saturation and did not undergo urgent BAS. In the former prenatal ultrasound reports, restrictive FO with subsequent urgent BAS was correctly predicted in 11 of 22 cases (50% sensitivity), whereas a normal FO anatomy was correctly predicted in 19 of 23 cases (83% specificity). After current re-analysis of the stored videos and images, we identified three highly significant markers for restrictive FO: a FO diameter < 7 mm (p < 0.01), a fixed (p = 0.035) and a hypermobile (p = 0.014) FO flap. The maximum systolic flow velocities in the pulmonary veins were also significantly increased in restrictive FO (p = 0.021), but no cut-off value to reliably predict restrictive FO could be identified. If the above markers are applied, all 22 cases with restrictive FO and all 23 cases with normal FO anatomy could correctly be predicted (100% positive predictive value). Correct prediction of urgent BAS also succeeded in all 22 cases with restrictive FO (100% PPV), but naturally failed in 4 of the 23 cases with correctly predicted normal FO ('bad mixer') (82.6% negative predictive value).

CONCLUSION

Precise assessment of FO size and FO flap motility allows a reliable prenatal prediction of both restrictive and normal FO anatomy postnatally. Prediction of likelihood of urgent BAS also succeeds reliably in all fetuses with restrictive FO, but identification of the small subset of fetuses that also requires urgent BAS despite their normal FO anatomy fails, because the ability of sufficient postnatal interatrial mixing cannot be predicted prenatally. Therefore, all fetuses with prenatally diagnosed d-TGA should always be delivered in a tertiary center with cardiac catheter stand-by, allowing BAS within the first 24 h after birth, regardless of their predicted FO anatomy.

Prenatal transposition of great arteries diagnosis and management: a Chinese single-center study

Objective

This study aimed to assess the diagnostic value of prenatal echocardiography for identifying transposition of the great arteries (TGA) during pregnancy and evaluating the associated outcomes.

Methods

We conducted a retrospective analysis of 121 prenatally diagnosed patients with TGA at our hospital between January 2012 and September 2022. This analysis included prenatal ultrasound, prenatal screening, clinical management and follow-up procedures.

Results

Among the 103 fetuses considered in the study, 90 (87.4%) were diagnosed with complete transposition of the great arteries (D-TGA), while 13 (12.6%) exhibited corrected transposition of the great arteries (CC-TGA). Diagnoses were distributed across the trimester, with 8 D-TGA and 2 CC-TGA patients identified in the first trimester, 68 D-TGA patients and 9 CC-TGA patients in the second trimester, and 14 D-TGA and 2 CC-TGA patients referred for diagnosis in the third trimester. Induction of labour was pursued for 76 D-TGA patients (84.4%) and 11 CC-TGA patients (84.6%), and 14 D-TGA patients (15.6%) and 2 CC-TGA patients (15.4%) continued pregnancy until delivery. Among the D-TGA patients, 9 fetuses (10.0%) underwent surgery, two of which were inadvertent fatality, while the remaining seven experienced positive outcomes. Additionally, seven TGA patients received palliative care, leading to four fatalities among D-TGA patients (5.2%), whereas 1 D-TGA patients and 2 CC-TGA patients survived.

Conclusion

This study underscores the feasibility of achieving an accurate prenatal diagnosis of TGA during early pregnancy. The utility of prenatal ultrasound in the development of personalized perinatal plans and the application of multidisciplinary treatment during delivery are conducive.

Cerebroplacental hemodynamics in fetuses with transposition of the great arteries and usefulness in predicting neonatal condition

OBJECTIVES

Literature on cerebroplacental hemodynamics in fetuses with transposition of the great arteries (TGA) is scarce and provides conflicting results regarding the presence of a brain-sparing effect. The aims of this study were to examine Doppler parameters in the middle cerebral artery (MCA) and umbilical artery (UA) in a large cohort of fetuses with TGA, and to assess their possible utility in predicting the need for urgent balloon atrial septostomy (BAS) in the neonate.

METHODS

This was a retrospective observational study of fetuses diagnosed with TGA between 2008 and 2022 and an age-matched cohort of normal fetuses, conducted in a single tertiary fetal cardiology center. Medical records and echocardiographic examinations were reviewed to collect demographic, sonographic and follow-up data. Selected Doppler parameters were compared between fetuses with TGA and normal fetuses, as well as between TGA fetuses with and those without an associated ventricular septal defect (VSD), to assess the impact of this congenital heart defect on cerebroplacental circulation. Additionally, Doppler indices in patients with a restrictive foramen ovale (FO) were analyzed to identify potential predictors of the need for urgent BAS.

RESULTS

A total of 541 examinations of 159 fetuses with TGA performed between 19 and 40 weeks' gestation and 1300 examinations of 1215 age-matched normal fetuses were included in the study. MCA pulsatility index (PI) and UA-PI followed expected trends throughout pregnancy, with slightly higher values observed in TGA fetuses, albeit within the limits for the normal population. Cerebroplacental ratio (CPR) values were similar in normal and TGA fetuses. The presence of a small VSD did not have a clinically significant impact on Doppler parameters. Peak systolic velocity (PSV) in the MCA increased gradually after 35 weeks' gestation, especially in fetuses that did not develop restriction of the FO after birth. MCA-PSV values below 1.16 multiples of the median measured at 38 weeks or later predicted the need for urgent BAS with 81.4% sensitivity and 52.4% specificity.

CONCLUSIONS

MCA-PI, UA-PI and CPR values in fetuses with TGA usually fall within normal limits throughout pregnancy. The presence of a small VSD does not affect the Doppler parameters significantly. MCA-PSV increases in TGA fetuses after 35 weeks, and its value measured at the last prenatal examination (ideally after 37 weeks) may serve as an additional predictive factor for the need for urgent BAS. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal cardiac and neonatal cerebral hemodynamics and oxygen metabolism in transposition of the great arteries

OBJECTIVES

Hemodynamic abnormalities and brain development disorders have been reported previously in fetuses and infants with transposition of the great arteries and intact ventricular septum (TGA-IVS). A ventricular septal defect (VSD) is thought to be an additional risk factor for adverse neurodevelopment, but literature describing this population is sparse. The objectives of this study were to assess fetal cardiac hemodynamics throughout pregnancy, to monitor cerebral hemodynamics and oxygen metabolism in neonates, and to compare these data between patients with TGA-IVS, those with TGA-VSD and age-matched controls.

METHODS

Cardiac hemodynamics were assessed in TGA-IVS and TGA-VSD fetuses and compared with healthy controls matched for gestational age (GA) during three periods: ≤ 22 + 5 weeks (GA1), 27 + 0 to 32 + 5 weeks (GA2) and ≥ 34 + 5 weeks (GA3). Left (LVO), right (RVO) and combined (CVO) ventricular outputs, ductus arteriosus flow (DAF, sum of ante- and retrograde flow in systole and diastole), diastolic DAF, transpulmonary flow (TPF) and foramen ovale diameter were measured. Aortic (AoF) and main pulmonary artery (MPAF) flows were derived as a percentage of CVO. Fetal middle cerebral artery and umbilical artery (UA) pulsatility indices (PI) were measured and the cerebroplacental ratio (CPR) was derived. Bedside optical brain monitoring was used to measure cerebral hemoglobin oxygen saturation (SO2 ) and an index of microvascular cerebral blood flow (CBFi ), along with peripheral arterial oxygen saturation (SpO2 ), in TGA-IVS and TGA-VSD neonates. Using hemoglobin (Hb) concentration measurements, these parameters were used to derive cerebral oxygen delivery and extraction fraction (OEF), as well as an index of cerebral oxygen metabolism (CMRO2i ). These data were acquired in the early preoperative period (within 3 days after birth and following balloon atrial septostomy) and compared with those of age-matched healthy controls, and repeat measurements were collected before discharge when vital signs were stable.

RESULTS

LVO was increased in both TGA groups compared with controls throughout pregnancy. Compared with controls, TPF was increased and diastolic DAF was decreased in TGA-IVS fetuses throughout pregnancy, but only during GA1 and GA2 in TGA-VSD fetuses. Compared with controls, DAF was decreased in TGA-IVS fetuses throughout pregnancy and in TGA-VSD fetuses at GA2 and GA3. At GA2, AoF was higher in TGA-IVS and TGA-VSD fetuses than in controls, while MPAF was lower. At GA3, RVO and CVO were higher in the TGA-IVS group than in the TGA-VSD group. In addition, UA-PI was lower at GA2 and CPR higher at GA3 in TGA-VSD fetuses compared with TGA-IVS fetuses. Within 3 days after birth, SpO2 and SO2 were lower in both TGA groups than in controls, while Hb, cerebral OEF and CMRO2i were higher. Preoperative SpO2 was also lower in TGA-VSD neonates than in those with TGA-IVS. From preoperative to predischarge periods, SpO2 and OEF increased in both TGA groups, but CBFi and CMRO2i increased only in the TGA-VSD group. During the predischarge period, SO2 was higher in TGA-IVS than in TGA-VSD neonates, while CBFi was lower.

CONCLUSIONS

Fetal cardiac and neonatal cerebral hemodynamic/metabolic differences were observed in both TGA groups compared with controls. Compared to those with TGA-IVS, fetuses with TGA-VSD had lower RVO and CVO in late gestation. A higher level of preoperative hypoxemia was observed in the TGA-VSD group. Postsurgical cerebral adaptive mechanisms probably differ between TGA groups. Patients with TGA-VSD have a specific physiology that warrants further study to improve neonatal care and neurodevelopmental outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Right ventricular systolic function and associated anatomic risk factors in fetuses with transposition of the great arteries: Evaluation by velocity vector imaging

Objectives

The aim of this study was to evaluate right ventricular (RV) systolic function in fetuses with transposition of the great arteries (TGA) using velocity vector imaging (VVI) and to investigate the impact of different factors on RV systolic function in TGA fetuses.

Methods

This was a retrospective cross-sectional study of fetuses referred to our tertiary center between 2015 and 2019. Maternal and fetal baseline characteristics and conventional echocardiographic and myocardial deformation indices were collected in fetuses with TGA at 20-28 weeks' gestation, which were compared with normal fetuses with comparable gestational age (GA). RV deformational parameters including global and regional longitudinal peak systolic strain, strain rate, and velocity were measured using off-line speckle tracking analysis. The univariate and multivariate linear regression analyses were established to evaluate the independent risk factors for RV global longitudinal systolic strain (RVGLSs) and strain rate (RVGLSRs).

Results

In total, 78 fetuses with TGA [including 49 fetuses with complete transposition of the great arteries (d-TGA) and 29 fetuses with Taussig-Bing anomaly (TBA)] and 49 normal fetuses were included. Compared with normal controls, global and most regional RV longitudinal systolic peak velocity, strain, and strain rate were lower in d-TGA and TBA fetuses (P < 0.05). Compared with normal controls, global and most regional RV longitudinal systolic strain was lower in d-TGA fetuses without pulmonary stenosis (PS) and ventricular septal defect (VSD), while RVGLSs and RVGLSRs were lower in TBA fetuses without PS. The VSD was an independent determinant of RVGLSRs (P = 0.024) in the d-TGA group. Additionally, PS was an independent determinant of RVGLSs and RVGLSRs (P = 0.012, P = 0.027) in the TBA group.

Conclusion

Early impairment of RV systolic function has already occurred in TGA fetuses during the 2nd trimester of pregnancy. PS, VSD, and foramen ovale (FO) were independent risk factors for decreased RV function.

Pulmonary hypertension associated with vein of Galen malformation. Fetal cardiac hemodynamic findings and physiological considerations

The management of newborns with vein of Galen aneurysmal malformation (VGAM) is clinically challenging for neonatologists and cardiologists. Hemodynamic profiles in four fetuses diagnosed with VGAM who subsequently developed neonatal cardiac failure and pulmonary hypertension were studied using two-dimensional and Doppler echocardiography. All four had an increased cardiothoracic ratio due to right ventricular dilatation on antenatal ultrasound. Doppler studies of the aortic isthmus were abnormal with retrograde flow starting in mid systole and throughout diastole. Left and right ventricular outputs were significantly increased. Net pulmonary flow was highly abnormal with a flow rate almost four times higher than normal. After a short period of clinical stability, all neonates developed cardiac failure and pulmonary hypertension. This article reviews VGAM pathophysiology and the potential relationship between pulmonary hypertension and VGAM, supporting early post-natal treatment of pulmonary hypertension and right ventricular failure.

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.