Atrioventricular block detected in fetal life: associated anomalies and potential prognostic markers

Fetal arrhythmias: Current evidence of prenatal diagnosis and management

Fetal arrhythmias present as an irregular cardiac rhythm and heart rate. Fetal echocardiography and cardiotocography play a pivotal role in diagnosing and managing fetal arrhythmia. Fetal magnetocardiography and electrocardiography can provide electrical assessment but have several limitations; thus, prenatal diagnosis of fetal arrhythmia remains challenging. Most cases of fetal arrhythmia have a structurally normal heart with isolated premature contractions that spontaneously resolve in utero or after birth without treatment. Despite the theoretical advantage of fetoplacental circulation, progression to heart failure or hydrops is found in fetuses with tachy- or bradyarrhythmia due to the limited heart rate reserve. There is a clear clinical consensus on the efficacy of transplacental antiarrhythmic therapy using digoxin, sotalol, and flecainide for fetal supraventricular tachyarrhythmia. A recent Japanese multicenter clinical trial confirmed the efficacy and safety of these agents. Fetal ventricular tachycardia is an infrequent occurrence but can be associated with heart failure, hydrops, and sudden death. It is important to search for long QT syndrome. Transplacental administration of magnesium, propranolol, mexiletine, and lidocaine, alone or in combination, has been attempted for fetal ventricular tachycardia. Fetal complete atrioventricular block is caused by maternal autoantibodies or fetal congenital heart defects and is irreversible. There is currently no consensus on the indications for fetal treatment, including beta-sympathomimetics for bradyarrhythmia. Dexamethasone and intravenous immunoglobulin have been used to prevent or treat atrioventricular block and myocarditis, but recent studies have not shown the efficacy of these agents.

Isolated non-immune-mediated second-degree atrioventricular block in the fetus: natural history and predictive factors for spontaneous recovery

OBJECTIVES

To determine the clinical course of fetal isolated non-immune-mediated second-degree atrioventricular block (AVB) and the factors associated with spontaneous recovery in these cases.

METHODS

Fetuses with isolated non-immune-mediated second-degree AVB were recruited prospectively between 2014 and 2022. These fetuses were divided into two groups: those which recovered spontaneously and those which did not. Maternal and fetal characteristics and intrauterine and postnatal outcomes were compared between the two groups.

RESULTS

The study cohort included 20 fetuses with isolated non-immune-mediated second-degree AVB, diagnosed at a median gestational age of 22.0 (range, 17.0-35.0) weeks. In 12 fetuses, 1:1 atrioventricular conduction was restored spontaneously in utero and there was no recurrence during the postnatal follow-up period. In the remaining eight fetuses, second-degree AVB was maintained and, in six of these, the pregnancy was terminated on parental request. Of the two liveborn children who had persistent second-degree AVB prenatally, one had progressed to complete AVB at the latest follow-up, at the age of 34 months, but was asymptomatic, without heart enlargement or dysfunction. The other child progressed to complete AVB after delivery and was diagnosed with type-2 long QT syndrome. This infant died aged 2 months. Fetuses in the group that recovered spontaneously had earlier gestational age at diagnosis (median, 20.0 (range, 17.0-26.0) vs 24.5 (range, 18.0-35.0) weeks; P = 0.004) and higher atrial rate at diagnosis (median, 147 (range, 130-160) vs 138 (range, 125-149) bpm; P = 0.006) in comparison with the group that did not recover spontaneously. The best cut-off values for prediction of failure to recover spontaneously were 22.5 weeks' gestational age at diagnosis and 144 bpm atrial rate at diagnosis, with sensitivities of 87.5% and 75.0%, respectively, and specificities of 92.0% and 87.5%, respectively.

CONCLUSIONS

The outcome of 60% of fetuses with isolated non-immune-mediated second-degree AVB was favorable. Earlier gestational age and higher atrial rate at diagnosis were associated with spontaneous reversion to normal sinus rhythm. Prenatal genetic testing should be performed in cases with persistent AVB, to exclude heritable disorders including long QT syndrome. These findings provide important information for clinical management and prenatal counseling in these cases. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Exploring the clinical characteristics and prevalence of the annular pancreas: a meta-analysis

BACKGROUND

The annular pancreas (AP) is a rare gastrointestinal congenital malformation, in which malrotation of the pancreatic ventral bud in the seventh week of embryonic development manifests in a partial or complete ring of tissue around the second part of the duodenum.

METHODS

The main online medical databases such as PubMed, ScienceDirect, Wiley online library, Web of Science, and EBSCO discovery service were used to gather all relevant studies on the AP.

RESULTS

A total of 12,729,118 patients were analyzed in relation to the prevalence of AP. The pooled prevalence of AP was 0.0045% (95% CI: 0.0021%-0.0077%). The most frequent comorbidity in adults and children was duodenal obstruction, with a pooled prevalence of 24.04% and 52.58%, respectively (95% CI: 6.86%-46.48% and 35.56%-69.31%, respectively). The most frequent operation in adult patients with AP was duodenojejunostomy, with pooled prevalence established at 3.62% (95% CI: 0.00%-10.74%).

CONCLUSION

The diagnostic complexity of AP is accentuated by its nonspecific clinical symptoms, making accurate identification reliant on imaging studies. Therefore, having a thorough knowledge of the clinical characteristics of the AP and its associated anomalies becomes paramount when faced with this rare congenital condition.

Prenatal diagnosis of fetal bradyarrhythmia and postnatal outcome

INTRODUCTION

Prenatal diagnosis of Fetal bradyarrhythmia leads to parental and care provider anxiety as data on outcome is scarce. We aimed to correlate the prenatal presentation of fetal bradyarrhythmia with postnatal outcome.

METHODS

Retrospective analysis of case records from 2017 to 2021. All fetuses with sustained bradyarrhythmia beyond 11 weeks were included in the study.

RESULTS

Twenty fetuses were identified: mean gestational age at diagnosis was 23 weeks 2 days. The type of bradyarrhythmia was as follows: Complete atrioventricular block 10 (50 %), Sinus Bradycardia 7 (35 %), second degree atrioventricular block 2 (10 %), and Unclassified 1 (5 %). In 10 fetuses, cardiac and extracardiac anatomy were normal; 8 fetuses (40 %) had cardiac anomalies,1 fetus had intraventricular hemorrhage and 1 had nuchal cystic hygroma. Among the fetuses with associated anomalies, there were 5 terminations of pregnancy (TOP), 1 intrauterine fetal demise (IUD), 3 neonatal demise (NND) and 1 livebirth. Among fetuses with normal anatomy, there were 2 TOP and 8 livebirths; five of the 10 mothers (50 %) tested positive for Anti Ro/La antibodies. All the 6 liveborn fetuses with complete atrioventricular block are on conservative management: 2 on metaproterenol and 4 on clinical follow up. Nine out of the 10 cases that had a postnatal paediatric cardiology assessment had a correct prenatal diagnosis.

CONCLUSION

Correct prenatal identification of fetal bradyarrhythmia is feasible in about 90 % of cases. The risk of postnatal pacemaker requirement appears to be low irrespective of maternal Anti Ro/La status.

Fetal heart block: Vaginal delivery an option

BACKGROUND

Fetal heart block (FHB) occurs in approximately 1:20 000 births and is associated with significant morbidity and mortality. Vaginal delivery with intrapartum fetal scalp lactate monitoring is offered as an option at our centre for selected cases, in contrast with the published literature advocating caesarean birth.

AIMS

To review perinatal outcomes at delivery for FHB at a tertiary referral hospital.

MATERIALS AND METHODS

Ours was a retrospective cohort study from 1 January, 2007 to 30 June, 2020. The infant outcomes are summarised in three delivery groups: vaginal delivery, planned caesarean section (CS) and unplanned CS.

RESULTS

There were 23 newborns in the study period, with a median gestation at birth of 37.2 weeks and there was one antepartum fetal death in this cohort. Vaginal delivery was planned in 12 women: eight had normal births, three of these women progressed to an intrapartum (unplanned) CS and one woman had a planned CS. All live babies in the vaginal delivery cohort had an Apgar score greater than seven at five minutes. Of the 22 newborns, six required intubation, of which five had been delivered by a planned CS.

CONCLUSION

Our data suggest that planned vaginal delivery is a safe option for selected women carrying a fetus with FHB. Managing labour with serial fetal scalp lactates, and the involvement of senior clinicians are important factors in achieving a successful outcome.

Prenatal Diagnosis of Fetal Heart Failure

Fetal heart failure (FHF) is a condition of inability of the fetal heart to deliver adequate blood flow for tissue perfusion in various organs, especially the brain, heart, liver and kidneys. FHF is associated with inadequate cardiac output, which is commonly encountered as the final outcome of several disorders and may lead to intrauterine fetal death or severe morbidity. Fetal echocardiography plays an important role in diagnosis of FHF as well as of the underlying causes. The main findings supporting the diagnosis of FHF include various signs of cardiac dysfunction, such as cardiomegaly, poor contractility, low cardiac output, increased central venous pressures, hydropic signs, and the findings of specific underlying disorders. This review will present a summary of the pathophysiology of fetal cardiac failure and practical points in fetal echocardiography for diagnosis of FHF, focusing on essential diagnostic techniques used in daily practice for evaluation of fetal cardiac function, such as myocardial performance index, arterial and systemic venous Doppler waveforms, shortening fraction, and cardiovascular profile score (CVPs), a combination of five echocardiographic markers indicative of fetal cardiovascular health. The common causes of FHF are reviewed and updated in detail, including fetal dysrhythmia, fetal anemia (e.g., alpha-thalassemia, parvovirus B19 infection, and twin anemia-polycythemia sequence), non-anemic volume load (e.g., twin-to-twin transfusion, arteriovenous malformations, and sacrococcygeal teratoma, etc.), increased afterload (intrauterine growth restriction and outflow tract obstruction, such as critical aortic stenosis), intrinsic myocardial disease (cardiomyopathies), congenital heart defects (Ebstein anomaly, hypoplastic heart, pulmonary stenosis with intact interventricular septum, etc.) and external cardiac compression. Understanding the pathophysiology and clinical courses of various etiologies of FHF can help physicians make prenatal diagnoses and serve as a guide for counseling, surveillance and management.

Transient Fetal Atrioventricular Block: A Series of Four Cases and Approach to Management

Fetal atrioventricular block (AVB) is a failure of conduction from atria to ventricles. Immune- and non-immune-mediated forms occur, especially in association with congenital heart disease. Second-degree (2°) AVB may be reversible with dexamethasone and IVIG in immune-mediated disease. However, once third-degree (3°) AVB develops, it is deemed irreversible with need for a pacemaker and risk for cardiomyopathy. Rarely, 2° AVB is a transient, benign phenomenon in the immature conduction system. Few case series of transient AVB have been reported, but a management approach has not been defined. We report four patients with self-resolving, non-immune fetal AVB and outline a management strategy. This article is protected by copyright. All rights reserved.

Longitudinal Analysis of Fetal Ventricular Rate for Risk Stratification in Immune Congenital Heart Block

OBJECTIVES

To assess the perinatal risks of immune complete congenital heart block (iCCHB) based on the longitudinal analysis of fetal heart rate.

METHODS

Retrospective analysis of a cohort of grade III congenital heart block diagnosed in utero, in the absence of associated cardiac defect, with positive maternal serum antibodies. Longitudinal measurements of the fetal heart rate were used to estimate the average slope of ventricular rate as a function of gestational age. We then defined the following prognostic stratification based on longitudinal follow-up observations: the high-rate (HR) group included cases for which all prenatal ventricular rate measurements were above the age-specific mean of our population of iCCHB and the low-rate (LR) group included those with at least one observation below the mean during follow-up. The 2 groups were compared to analyze the potential relationship between prenatal ventricular rate and adverse neonatal outcome defined by in utero or perinatal death, neonatal heart rate <50 bpm, or hemodynamic failure requiring emergency pacing.

RESULTS

Forty-four cases were studied. Overall, the average heart rate significantly decreased during gestation from 65 bpm at 20 weeks to 55 bpm at 38 weeks. The HR and LR groups included 18 (41%) and 26 (59%) cases, respectively. Adverse perinatal outcome occurred in 1/18 (6%) and 22/26 (85%) cases in the HR and LR groups, respectively (p < 0.001). In the HR group, 33% of cases remained nonpaced at >6 months. The positive predictive values and negative predictive values for adverse perinatal outcome in the LR group were 85% (22/26) and 94% (17/18), respectively (100 and 80% <30 weeks and 88 and 78% at ≥30 weeks).

CONCLUSIONS

The prognostic classification we developed based on longitudinal heart rate assessment may be used in the late 2nd or early 3rd trimester to identify iCCHB cases at high risk of adverse perinatal outcome. This prognostic stratification should help refine counseling and perinatal management earlier in pregnancy instead of waiting for late gestation or predelivery assessment.

No. 363-Investigation and Management of Non-immune Fetal Hydrops

OBJECTIVE

To describe the current investigation and management of non-immune fetal hydrops with a focus on treatable or recurring etiologies.

OUTCOMES

To provide better counselling and management in cases of prenatally diagnosed non-immune hydrops.

EVIDENCE

Published literature was retrieved through searches of PubMed or MEDLINE, CINAHL, and The Cochrane Library in 2017 using key words (non-immune hydrops fetalis, fetal hydrops, fetal therapy, fetal metabolism). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, observational studies, and significant case reports. Additional publications were identified from the bibliographies of these articles. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to September 2017. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinicalpractice guideline collections, clinical trial registries, and national and international medical specialty societies.

BENEFITS, HARMS, AND COSTS

These guidelines educate readers about the causes of non-immune fetal hydrops and its prenatal counselling and management. It also provides a standardized approach to non-immune fetal hydrops, emphasizing the search for prenatally treatable conditions and recurrent genetic etiologies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care.

RECOMMENDATIONS

Separation of Fetal-ECG From Single-Channel Abdominal ECG Using Activation Scaled Non-Negative Matrix Factorization

Performing a fetal electrocardiogram (ECG) analysis, which contains important information about the status of a fetal, can help to detect fetus health even before birth. Since the fetal ECG extracted from the ECG signal recorded from the mother's abdomen, this extraction problem can be seen as a source separation problem, of recovering source signals from signal mixtures. In this paper, a method for separation of fetal ECG from abdominal ECG using activation scaled non-negative matrix factorization (NMF) is proposed. The performance of the proposed method is also compared with independent component analysis. The proposed method is tested under three different scenarios. First, the original abdominal ECG signal is used for fetal separation. Second, the recovered abdominal ECG after compression is used for separation. Third, the fetal ECG is extracted from the compressed domain of the abdominal ECG. We applied scaling on the activation matrix obtained using NMF for emphasizing the fetal ECG present in abdominal ECG. The improved-regularized least-squares [Formula: see text] algorithm is used for signal reconstruction, which provides better reconstruction quality and less processing time in comparison with other existing methods. The proposed algorithm is evaluated and tested on real abdominal recordings obtained from two different datasets from Physionet. The first dataset used for this paper is Silesia dataset for abdominal and direct f-ECG, and the second dataset we considered is Set-A of the Physionet challenge. The obtained outcomes reveal that it is possible to separate fetal ECG from single-channel abdominal ECG signal, which can help us to achieve energy-efficient transmission, and cost-effective fetal ECG remote monitoring for Internet-of-Things applications, where device battery and computational capacity are limited.

N° 363 - Évaluation et prise en charge de l'anasarque fœtoplacentaire non immune

OBJECTIF

Décrire les méthodes actuelles d'évaluation et de prise en charge de l'anasarque fœtoplacentaire non immune en mettant l'accent sur les étiologies traitables ou récurrentes. RéSULTATS: Offrir de meilleurs services de conseil et de prise en charge en cas d'anasarque fœtoplacentaire non immune diagnostiquée en période prénatale. DONNéES: La littérature publiée a été récupérée au moyen de recherches menées dans PubMed, MEDLINE, CINAHL, et la Bibliothèque Cochrane en 2017 à l'aide de mots-clés (« non-immune hydrops fetalis », « fetal hydrops », « fetal therapy », « fetal metabolism »). Les articles retenus portaient sur des revues systématiques, des essais cliniques contrôlés, randomisés ou non, des études observationnelles et des études de cas importantes. D'autres publications ont été repérées dans les bibliographies de ces articles. Aucune restriction de date ou de langue n'a été employée. Les recherches ont été mis à jour régulièrement, et les résultats ont été incorporés à la directive clinique jusqu'en septembre 2017. Nous avons également tenu compte de la littérature grise (non publiée) trouvée sur les sites Web d'organismes d'évaluation des technologies de la santé et d'autres organismes liés aux technologies de la santé, dans des collections de directives cliniques et des registres d'essais cliniques, et obtenue auprès d'associations nationales et internationales de médecins spécialistes. AVANTAGES, INCONVéNIENTS ET COûTS: La présente directive clinique renseigne les lecteurs sur les causes de l'anasarque fœtoplacentaire non immune ainsi que sur son évaluation et sa prise en charge. Elle propose également une approche standardisée d'évaluation et de prise en charge, et met l'accent sur la recherche des conditions traitables en période prénatale et des étiologies génétiques récurrentes.

VALEURS

La qualité des données probantes a été évaluée en fonction des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs. RECOMMANDATIONS.

The use of non-invasive fetal electrocardiography in diagnosing second-degree fetal atrioventricular block

Background

Complete atrioventricular block in fetuses is known to be mostly associated with autoimmune disease and can be irreversible if no steroids treatment is provided. Conventional methods used in clinical practice for diagnosing fetal arrhythmia are limited since they do not reflect the primary electrophysiological conduction processes that take place in the myocardium. The non-invasive fetal electrocardiogram has the potential to better support fetal arrhythmias diagnosis through the continuous analysis of the beat to beat variation of the fetal heart rate and morphological analysis of the PQRST complex.

Case presentation

We present two retrospective case reports on which atrioventricular block diagnosis could have been supported by the non-invasive fetal electrocardiogram. The two cases comprised a 22-year-old pregnant woman with the gestational age of 31 weeks and a 25-year-old pregnant woman with the gestational age of 41 weeks. Both women were admitted to the Department of Maternal and Fetal Medicine at the Kyiv and Kharkiv municipal perinatal clinics. Patients were observed using standard fetal monitoring methods as well as the non-invasive fetal electrocardiogram. The non-invasive fetal electrocardiographic recordings were analyzed retrospectively, where it is possible to identify the presence of the atrioventricular block.

Conclusions

This study demonstrates, for the first time, the feasibility of the non-invasive fetal electrocardiogram as a supplementary method to diagnose of the fetal atrioventricular block. Combined with current fetal monitoring techniques, non-invasive fetal electrocardiography could support clinical decisions.

Spontaneous Remission of Congenital Complete Atrioventricular Block in Anti-Ro/La Antibody-Negative Monozygotic Twins: Case Report

Background:

Congenital complete atrioventricular block without any structural heart disease and anti-Ro/La negativity is very rare. Discordant complete atrioventricular block, which is more frequently defined in the literature as an autoimmune mechanism, is much more rare in monozygotic twins.

Case Report:

The 26-year-old healthy mother had given birth in her first spontaneous, uneventful pregnancy to monozygotic twins at week 35. While the first twin’s physical examination proved her to be normal with a pulse rate consistent with her age, the second twin had a pulse rate of approximately 40 beats/minute.The patient was confirmed to have congenital complete atrioventricular block.

Conclusion:

Despite this case appears to be an isolated one, a discordant complete atrioventricular block regression without any autoimmune evidence should be included in the differential diagnosis of bradycardia in infants.

Fetal and Neonatal Arrhythmias

Cardiac arrhythmias are an important aspect of fetal and neonatal medicine. Premature complexes of atrial or ventricular origin are the main cause of an irregular heart rhythm. The finding is typically unrelated to an identifiable cause and no treatment is required. Tachyarrhythmia most commonly relates to supraventricular reentrant tachycardia, atrial flutter, and sinus tachycardia. Several antiarrhythmic agents are available for the perinatal treatment of tachyarrhythmias. Enduring bradycardia may result from sinus node dysfunction, complete heart block and nonconducted atrial bigeminy as the main arrhythmia mechanisms. The management and outcome of bradycardia depend on the underlying mechanism.

Clinical course and outcome of antenatally detected atrioventricular block: experience of a single tertiary centre and review of the literature

OBJECTIVE

The objective is to study the course and outcome of fetuses with congenital atrioventricular block (AVB) in a single centre.

METHODS

Retrospective analysis of cases diagnosed prenatally with second and third degree AVB. The clinical characteristics and outcome of fetal AVB were evaluated including in utero treatment.

RESULTS

Sixty-two cases were studied. AVB was associated with a congenital heart defect (CHD-AVB) in 17 cases (27%), whereas it was isolated (i-AVB) in 45 (73%), 42 of which were associated with maternal antibodies. There were nine (52.9%) live births in the CHD-AVB group, five of which (55%) resulted in infant deaths. In the i-AVB group, there were 40/45 (88.9%) live births and 1/40 (2.5%) infant death; 36 (90%) babies required a permanent pacemaker. The only factor predictive of postnatal death was the presence of CHD (5/9 vs 1/39 or 48.7 [3.6; 1457.7], p < 0.001). Nineteen fetuses (40.5%) with i-AVB received steroids in utero. No difference in outcome was found between the AVB treated in utero versus the no-treatment group in terms of permanent pacemaker placement, postnatal death or development of dilated cardiomyopathy.

CONCLUSION

The most important prognostic factor for congenital AVB is the association with CHD. In utero treatment remains questionable.

Effect of dual-chamber pacemaker implantation on aortic dilatation in patients with congenital heart block

Ascending aortic dilatation (AoD) in patients with structurally normal hearts and congenital heart block (CHB) has been previously described. The cause and management of AoD are yet to be determined. The aim of this study was to test the hypothesis that AoD in children with CHB regresses after the implantation of cardiac dual-chamber pacemakers (PMs). The secondary hypothesis was an association between the presence of maternal antibodies (SS-A or SS-B) and the degree of aortic dilatation. Clinical data with echocardiographic correlates of patients with CHB followed at a single institution were retrospectively reviewed. Comparison of the target structures diameter was based on 3 different z-score equations, with AoD defined as a z score >2. Inclusion criteria were CHB diagnosis by 12-lead electrocardiography or Holter recording and benefit from a permanent dual-chamber PM. Excluded were patients with incomplete echocardiographic measurements, those with major structural heart defects, and those with syndromes or diseases known to be associated with AoD. There were 17 patients, diagnosed at a median age of 6 months (interquartile range 0 to 47.8). Maternal antibodies were positive in 6 patients and negative in 11. All patients underwent PM implantation at a median age of 4.5 years (interquartile range 1.4 to 7.9). AoD (z score >2.0 according to 3 different equations) was present in 35% to 59% of patients. There was a significant reduction of mean ascending aortic z score in patients with AoD from 4.66 to 3.67 (p = 0.06), from 4.82 to 2.95 (p = 0.002), and from 6.07 to 3.39 (p = 0.006) according to the various z-score equations. Most patients with positive serology had AoD, without reaching statistical significance. In conclusion, AoD is associated with CHB, more likely in infants exposed to maternal antibodies. AoD decreases after the implantation of a PM. This is probably related to the regularization of stroke volume.

Perinatal and infant outcomes of prenatal diagnosis of heterotaxy syndrome (asplenia and polysplenia)

Patients with heterotaxy syndrome (HS) have a range of anomalies and outcomes. There are limited data on perinatal outcomes after prenatal diagnosis. To determine the factors influencing perinatal and infant outcomes, we analyzed prenatal and postnatal variables in fetuses with HS from 1995 to 2011. Of 154 fetuses with HS, 61 (40%) had asplenia syndrome (ASP) and 93 (60%) had polysplenia syndrome (PSP). In the ASP group, 22 (36%) patients were elected for termination of pregnancy, 4 (10%) had fetal death, and 35 of 39 (90%) continued pregnancies were live born. In the PSP group, 12 (13%) patients were elected for termination of pregnancy, 5 (6%) had fetal death (4 with bradyarrhythmia), and 76 of 81 (94%) continued pregnancies were live born. Bradyarrhythmia was the only predictor of fetal death. In the live-born ASP group, 43% (15 of 35) died, 7 because of pulmonary vein stenosis, 4 postoperatively, and 4 because of noncardiac causes. In the live-born PSP group, 13% (10 of 76) died, 5 postoperatively, 2 from bradyarrhythmia, 1 from a cardiac event, and 2 from noncardiac causes. Pulmonary vein stenosis and noncardiac anomalies were independent risk factors for postnatal death. Only 8% of ASP patients achieved biventricular circulation, compared with 65% of PSP patients. In the live-born cohort, the 5-year survival rate was 53% for ASP and 86% for PSP. In conclusion, most PSP patients are currently alive with biventricular circulation in contrast with few ASP patients. Bradyarrhythmia was the only predictor of fetal death. Pulmonary vein stenosis and noncardiac anomalies were predictors of postnatal death.

Perinatal outcome in fetuses with heterotaxy syndrome and atrioventricular block or bradycardia

Congenital atrioventricular (AV) block is commonly associated with heterotaxy syndrome; together they have reportedly low survival rates (10-25%). However, information about perinatal outcome and predictors of non-survival after prenatal diagnosis of this association is scarce. Therefore, we studied fetuses with heterotaxy syndrome and bradycardia or AV-block diagnosed between 1995 and 2011, and analyzed pre and post-natal variables. The primary outcome was death and the secondary outcome was pacemaker placement. Of the 154 fetuses with heterotaxy syndrome, 91 had polysplenia syndrome, 22/91(24%) with bradycardia or AV-block. Thirteen (59%) patients had sinus bradycardia at diagnosis, 8 (36%) complete AV block, and 1 (5%) second-degree AV-block. Three patients elected for termination of pregnancy (3/22, 14%), 4 had spontaneous fetal demise (4/22, 18%), and 15 (15/22, 68%) were live-born. Of the fetuses with bradycardia/AV-block, 30% presented with hydrops, 20% had ventricular rates <55 beats/min, and 10% had cardiac dysfunction. Excluding termination of pregnancy, 15/19 fetuses (79%) survived to birth. Among the 15 live-born patients, 4 had bradycardia and 11 had AV-block. A further 3 patients died in infancy, all with AV-block who required pacemakers in the neonatal period. Thus, the 1-year survival rate, excluding termination of pregnancy, was 63% (12/19). Of the remaining 12 patients, 9 required pacemaker. Predictors of perinatal death included hydrops (p < 0.0001), ventricular dysfunction (p = 0.002), prematurity (p = 0.04), and low ventricular rates (p = 0.04). In conclusion, we found a higher survival rate (63%) than previously published in patients with heterotaxy syndrome and AV block or bradycardia diagnosed prenatally. Hydrops, cardiac dysfunction, prematurity and low ventricular rates were predictors of death.

Atrioventricular block during fetal life

Congenital complete atrioventricular (AV) block occurs in approximately 1 in 20,000 live births and is known to result in significant mortality and morbidity both during fetal life and postnatally. Complete AV block can occur as a result of an immune or a non-immune mediated process. Immune mediated AV block is a multifactorial disease, but is associated with the trans-placental passage of maternal autoantibodies (anti-Ro/SSA and/or anti-La/SSB). These autoantibodies attach to and subsequently damage the cardiomyocytes and conduction tissue in susceptible fetuses. In this report, we examine the evidence in reference to means of assessment, pathophysiology, and potential prenatal therapy of atrioventricular block.

Remission of congenital complete heart block without anti-Ro/La antibodies: A case report

Anti-Ro/La negative congenital heart block (CHB) is uncommon. We report one such case of CHB, with no associated structural heart disease or maternal autoantibodies. The heart block reverted to sinus rhythm spontaneously at two weeks of age, and the patient remains in sinus rhythm at a one year followup. Whether patients with antibody negative complete heart block have a different clinical course is conjectural.

Isolated Atrioventricular Block in the Fetus

Background—

Isolated complete atrioventricular block in the fetus is a rare but potentially lethal condition in which the effect of steroid treatment on outcome is unclear. The objective of this work was to study risk factors associated with death and the influence of steroid treatment on outcome.

Methods and Results—

We studied 175 fetuses diagnosed with second- or third-degree atrioventricular block (2000–2007) retrospectively in a multinational, multicenter setting. In 80% of 162 pregnancies with documented antibody status, atrioventricular block was associated with maternal anti-Ro/SSA antibodies. Sixty-seven cases (38%) were treated with fluorinated corticosteroids for a median of 10 weeks (1–21 weeks). Ninety-one percent were alive at birth, and survival in the neonatal period was 93%, similar in steroid-treated and untreated fetuses, regardless of degree of block and/or presence of anti-Ro/SSA. Variables associated with death were gestational age <20 weeks, ventricular rate ≤50 bpm, fetal hydrops, and impaired left ventricular function at diagnosis. The presence of ≥1 of these variables was associated with a 10-fold increase in mortality before birth and a 6-fold increase in the neonatal period independently of treatment. Except for a lower gestational age at diagnosis in treated than untreated (23.4±2.9 versus 24.9±4.9 weeks; P =0.02), risk factors were distributed equally between treatment groups. Two-thirds of survivors had a pacemaker by 1 year of age; 8 children developed cardiomyopathy.

Conclusions—

Risk factors associated with a poor outcome were gestation <20 weeks, ventricular rate ≤50 bpm, hydrops, and impaired left ventricular function. No significant effect of treatment with fluorinated corticosteroids was seen.

Hypoplastic left heart syndrome with restrictive atrial septum and advanced heart block documented with a novel fetal electrocardiographic monitor

Hypoplastic left ventricle with congenital heart block has been reported previously in a fetus with concurrent left atrial isomerism and levo-transposition of the great arteries. We present the unusual case of an infant diagnosed in utero with hypoplastic left heart syndrome, a restrictive atrial septum and advanced heart block but with D-looping of the ventricles and no atrial isomerism. In addition, fetal heart rhythm was documented with the assistance of a new fetal electrocardiographic monitor.

Impact of fetal echocardiography

Prenatal diagnosis of congenital heart disease is now well established for a wide range of cardiac anomalies. Diagnosis of congenital heart disease during fetal life not only identifies the cardiac lesion but may also lead to detection of associated abnormalities. This information allows a detailed discussion of the prognosis with parents. For continuing pregnancies, appropriate preparation can be made to optimize the postnatal outcome. Reduced morbidity and mortality, following antenatal diagnosis, has been reported for coarctation of the aorta, hypoplastic left heart syndrome, and transposition of the great arteries. With regard to screening policy, most affected fetuses are in the “low risk” population, emphasizing the importance of appropriate training for those who undertake such obstetric anomaly scans. As a minimum, the four chamber view of the fetal heart should be incorporated into midtrimester anomaly scans, and where feasible, views of the outflow tracts should also be included, to increase the diagnostic yield. Newer screening techniques, such as measurement of nuchal translucency, may contribute to identification of fetuses at high risk for congenital heart disease and prompt referral for detailed cardiac assessment.

Prenatal diagnosis, management and outcome of fetal dysrhythmia: a tertiary fetal medicine centre experience over an eight-year period

OBJECTIVE

To review the prenatal diagnosis, management and outcome of fetal dysrhythmia.

SUBJECTS AND METHODS

Prenatal diagnosis, management and outcomes of fetuses with dysrhythmia were reviewed retrospectively (01/01/1997 to 31/12/2004).

RESULTS

Over an 8-year period, 318 pregnant mothers were referred for assessment of suspected fetal dysrhythmias. Median gestation was 30 weeks (range 19-41). Fetal dysrhythmia was identified in 182 (57%) and classified as: (i) 126 atrial extrasystoles; (ii) 26 tachyarrhythmia, and (iii) 30 bradyarrhythmia. Of the fetuses with tachyarrhythmia, 23 had supraventricular tachycardia (SVT), 2 atrial flutter and 1 sinus tachycardia. One death associated with severe hydrops occurred in the tachyarrhythmia group. 19 cases of SVT were successfully treated in utero. Both cases of atrial flutter required direct current cardioversion in the neonatal period. In the bradyarrhythmia group, there were 15 isolated cases and 10 cases associated with congenital heart disease, with 73 and 20% survival, respectively.

CONCLUSIONS

Benign atrial extrasystoles are the commonest cause for referral and assessment of fetal dysrhythmia. The overall prognosis for SVT is good with the majority responding to transplacental therapy. In cases with congenital atrioventricular block, the outcome was less favourable, especially when the atrioventricular block was associated with congenital heart disease.

Fetal cardiac arrhythmia detection and in utero therapy

The human fetal heart develops arrhythmias and conduction disturbances in response to ischemia, inflammation, electrolyte disturbances, altered load states, structural defects, inherited genetic conditions, and many other causes. Yet sinus rhythm is present without altered rate or rhythm in some of the most serious electrophysiological diseases, which makes detection of diseases of the fetal conduction system challenging in the absence of magnetocardiographic or electrocardiographic recording techniques. Life-threatening changes in QRS or QT intervals can be completely unrecognized if heart rate is the only feature to be altered. For many fetal arrhythmias, echocardiography alone can assess important clinical parameters for diagnosis. Appropriate treatment of the fetus requires awareness of arrhythmia characteristics, mechanisms, and potential associations. Criteria to define fetal bradycardia specific to gestational age are now available and may allow detection of ion channelopathies, which are associated with fetal and neonatal bradycardia. Ectopic beats, once thought to be entirely benign, are now recognized to have important pathologic associations. Fetal tachyarrhythmias can now be defined precisely for mechanism-specific therapy and for subsequent monitoring of response. This article reviews the current and future diagnostic techniques and pharmacologic treatments for fetal arrhythmia.

Resumption of sinus rhythm from fetal complete atrioventricular block after maternally administered ritodrine

Reports have indicated that maternal administration of ritodrine increased the ventricular rate and thus ameliorated signs of heart failure in a fetus with complete atrioventricular block (CAVB). A fetus from a mother without the anti-SS-A/SS-B antibody had CAVB, with atrial rate 148-154 bpm and ventricular rate 53-57 bpm. After maternal administration of ritodrine, the ventricular rate increased to 60-65 bpm, and then sinus rhythm resumed. Ritodrine may not only increase the ventricular rate but also induce sinus rhythm in a fetus with CAVB.

Causes and consequences of 93 fetuses with cardiomegaly in a tertiary center in Thailand

OBJECTIVES

To assess etiology, perinatal mortality and associated factors of fetal cardiomegaly (FC).

METHODS

A retrospective study of fetuses with cardiomegaly was conducted. Demographic data, ultrasonographic findings, and outcomes were collected and analyzed.

RESULTS

Ninety-three fetuses were analyzed. The causes of FC were cardiac causes 49.5%, Bart's hemoglobinopathies 28%, and non-Bart's anemia 15%. Ascites, pericardial effusion, and hydrops were more prevalent in fetuses with anemia than those with cardiac abnormalities. The overall perinatal mortality was 69.9%. Although all Bart's hydrops died, perinatal mortality of non-Bart's anemia, and structural cardiac defect were 57.1 and 69.7%, respectively. Excluding Bart's anemia, receiver-operating characteristic curve analysis demonstrated that cardiothoracic ratio of ≥0.58 best predictive for perinatal mortality. Earlier gestational age at diagnosis, skin edema, and chromosomal abnormality were associated with higher mortality.

CONCLUSIONS

Majority causes of FC were cardiac and anemic in origin. It carried high-perinatal mortality depending on the causes.

Congenital heart block not associated with anti-Ro/La antibodies: comparison with anti-Ro/La-positive cases

OBJECTIVE

To study anti-Ro/La-negative congenital heart block (CHB).

METHODS

Forty-five fetuses with CHB were evaluated by analysis of anti-Ro/La antibodies using sensitive laboratory methods.

RESULTS

There were 9 cases of anti-Ro/La-negative CHB; 3 died (33.3%). Only 3 (33.3%) were complete in utero and 5 (55.5%) were unstable. No specific etiology was diagnosed. Six infants (66.6%) were given pacemakers. There were 36 cases of anti-Ro/La-positive CHB. All except 2 infants (94.4%) had complete atrioventricular block in utero. Ten died (27.8%), one (2.7%) developed severe dilated cardiomyopathy, and 26 (72.2%) were given pacemakers.

CONCLUSION

Nine of the 45 consecutive CHB cases (20%) were anti-Ro/La-negative with no known cause. They were less stable and complete than the anti-Ro/La positive cases.

[Fetal ultrasonography and Doppler in isolated congenital heart block]

Isolated congenital heart block is linked to transplacental passage of maternal anti-SSA/Ro and/or anti-SSB/La antibodies that may be related to a connective tissue disease. Ultrasonography and Doppler are essential to screen fetus at risk. They allow the diagnosis of first- and second-degree blocks which are probably preliminary stages in conducting tissue's injury. In these situations, a maternal treatment by fluorinated steroids can be proposed because of its possible effect on partial blocks. However, these early signs of nodal injury can be lacking: some fetus present a complete heart block without previously detected less advanced block. Moreover, the significance of first-degree block is unclear since it could reverse spontaneously. Other markers of nodal injury would be valuable. In case of complete congenital heart block, ultrasonography is useful to detect congestive heart failure and help the obstetrical management when unfavorable prognostic signs occur.

Fetal dysrhythmias

Fetal cardiac dysrhythmias are potentially life-threatening conditions. However, intermittent extrasystoles, which are frequently encountered in clinical practice, do not require treatment. Sustained forms of brady- and tachyarrhythmias might require fetal intervention. Fetal echocardiography is essential not only to establish the diagnosis but also to monitor fetal response to therapy. In the last decade, improvements in ultrasound methodology and new diagnostic tools have contributed to better diagnostic accuracy and to a greater understanding of the electrophysiological mechanisms involved in fetal cardiac dysrhythmias. The most common form of supraventricular tachycardia - that caused by an atrioventricular re-entry circuit - should be differentiated from other forms of tachyarrhythmias, such as atrial flutter and atrial ectopic tachycardia. Ventricular tachycardia is rare in the fetus. Sustained tachycardias, intermittent or not, might be associated with the development of congestive heart failure and hydrops fetalis. Prompt treatment with either anti-arrhythmic drugs or delivery must be considered. Persistent fetal bradycardias associated with complete heart block are also potentially dangerous, whereas bradyarrhythmia due to blocked ectopy is well tolerated in pregnancy. Heart block can be associated with maternal anti-Ro/La autoantibodies or develop in fetuses with left atrial isomerism or with malformations involving the atrioventricular junction. The treatment of fetuses with immune-mediated heart block remains debatable. The use of antenatal steroid therapy is not widely accepted and there is concern over the risks and benefits of its use in the fetus. Direct fetal cardiac pacing has rarely been attempted.

Perinatal outcome of fetal atrioventricular block: one-hundred-sixteen cases from a single institution

BACKGROUND

Fetal atrioventricular (AV) block is an uncommon lesion with significant mortality. Because of the rarity of this disorder, the natural course, extensive evaluation of untreated fetuses, and late follow-up remain unclear.

METHODS AND RESULTS

Of the 116 consecutive cases of fetal AV block studied from 1988 to 2006, only 1 was terminated, and 75% were live births. Fifty-nine cases of AV block were associated with major structural heart disease, mainly left atrial isomerism (n=40), with only 26% of neonatal survivors. Of the 57 fetuses with normal cardiac anatomy, 41 (72%) were positive for maternal antinuclear antibodies, and 32 of these seropositive mothers did not receive any treatment. This untreated group had live-birth and 1-year infant survival rates of 93% and 90% [corrected], respectively. Five fetuses from seronegative mothers showed regression to sinus rhythm during pregnancy. The presence of major structural heart disease, hydrops, an atrial rate

CONCLUSIONS

This long-term study confirms that fetal AV block has a poor outcome when associated with structural heart disease and that spontaneous regression of AV block is possible in seronegative forms. The survival rate of >90% of our untreated patients with isolated forms of AV block raises concerns about any decision to intervene with immunosuppressive agents.

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Key Words Collapse

MESH Headings

• Atrioventricular Block/diagnostic imaging
• Atrioventricular Block/therapy
• Echocardiography, Doppler, Color/methods
• Female
• Fetal Diseases/diagnostic imaging
• Fetal Diseases/therapy
• Follow-Up Studies
• Hospitals, University/trends
• Humans
• Infant
• Perinatal Care/methods
• Perinatal Care/trends
• Pregnancy
• Retrospective Studies
• Treatment Outcome
• Ultrasonography, Prenatal/methods

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Grants Collapse

Affiliation(s)

Lilian M Lopes Department of Obstetrics and Gynecology, Fetal Medicine and Cardiology Unit, São Paulo University Medical School, São Paulo, SP, Brazil.
Gláucia Maria Penha Tavares
Ana Paula Damiano
Marco Antônio Borges Lopes
Vera Demarchi Aiello
Regina Schultz
Marcelo Zugaib

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Detection and management of life threatening arrhythmias in the perinatal period

The management of tachyarrhythmias and bradyarrythmias in the fetus requires a team approach with careful monitoring of fetal well-being as well as care in establishing a precise diagnosis with use of m-mode and Doppler echocardiography to determine the atrial and ventricular rate. A persistent fetal heart rate less than 80 beats per minute (bpm) suggests complete atrioventricular block. A persistent fetal heart rate over 180 bpm suggests pathological tachycardia, most of which are a supraventricular tachycardia mediated via an accessory pathway. However, around 20% are due to atrial flutter, and this review highlights why medical management should be different for these cases, and for those with hydrops or cardiac failure. It also illustrates which fetus or infant may be at particular risk, and illustrates key features in their management before and after birth.

Fetus with heart failure due to congenital atrioventricular block treated by maternally administered ritodrine

BACKGROUND

The efficacy of maternal administration of ritodrine in cases of congenital atrioventricular block (CAVB), especially with fetal heart failure, is not yet determined.

CASE

At 21 2/7 weeks of gestation, isolated CAVB with a ventricular/atrial rate of 55-70/130-140 bpm was found in a fetus from a 30-year-old Japanese nulliparous woman with anti-SSA antibody. Cardiothoracic area ratio (CTAR) was 40% and no fetal hydrops was observed. At 30 2/7 weeks, the ventricular rate decreased to 49 bpm with an atrial rate of 125 bpm. CTAR increased to 53.8% and ascites appeared. Maternal continuous ritodrine infusion was started with rapid improvement of fetal cardiac function; increment in the ventricular rate to 57 bpm and atrial rate to 137 bpm, with a decrement in CTAR to 44.6%. Ascites also gradually decreased and by the fourth day, it had completely disappeared with CTAR of 40.2%. On the 12th day after ritodrine treatment (32 1/7), amniotic fluid volume decreased and fetal weight gain stopped, which led us to assume a worsening intrauterine environment, and cesarean section was performed. A 1,178 g male infant was born with a 5-min Apgar score of 8. Continuous isoproterenol infusion was started, increasing the ventricular rate from 71 to 80 bpm. Pacemaker implantation is under consideration to treat this infant.

CONCLUSION

Maternal administration of ritodrine not only increased the fetal heart rate but also ameliorated the signs of fetal heart failure, and thus is considered one treatment of choice in CAVB.

FETAL BRADYCARDIA. A PRACTICAL APPROACH

Fetal bradycardia may herald fetal demise. This article highlights arrhythmic fetal bradycardia rather than bradycardia caused by perinatal distress. We briefly examine the embryonic conduction system's development and physiology and we review the classification, aetiology, evaluation, and approach to fetal bradycardia. Our aim is to provide the clinician with practical information about fetal bradycardia that enlightens causative conditions and aids management.

Pediatric arrhythmias: which are the news?

Knowledge about cardiac arrhythmias has significantly improved in the last 20 years, and the improvements in diagnosis and in therapy have also had important effects on the management of pediatric arrhythmias. In this paper, the most important developments in the field of management of pediatric arrhythmias (fetal arrhythmias, genetics, pharmacological strategies, radiofrequency ablation, new technologies) as well as the remaining problems (risk stratification of some arrhythmic forms as for example Wolff-Parkinson-White and ventricular arrhythmias) will be discussed.

Outcome of fetal cardiac defects

PURPOSE OF REVIEW

The present review summarizes the prenatal and postnatal outcome of cardiac anomalies and sustained arrhythmias diagnosed during fetal life.

RECENT FINDINGS

The outcome of sustained fetal arrhythmias has improved with greater experience using Sotalol for atrial flutter, and digoxin and amiodarone for 1: 1 reciprocating tachycardia. The outcome of fetal conduction system disease secondary to maternal Sjögren's antibodies has noticeably improved with transplacental dexamethasone. The postnatal prognosis for atrioventricular block associated with left atrial isomerism, however, remains very bleak. Assessing the effect of prenatal diagnosis on the outcome of structural defects remains difficult because of the high number of extracardiac anomalies and chromosome defects in this group. Preoperative survival is improved, but postoperative mortality has not improved. One clear advantage of prenatal diagnosis is the selection of fetuses that may benefit from in-utero intervention to limit the progression of their disease or lessen its severity at birth.

SUMMARY

For the most part, postoperative mortality of structural cardiac defects is not significantly improved by prenatal diagnosis. In-utero management of tachyarrhythmias and conduction system disease has improved postnatal outcome, except for the fetus with atrioventricular block and left atrial isomerism.

Congenital complete heart block and maternal connective tissue disease

Congenital complete heart block can be isolated or can occur in association with other structural heart diseases. Isolated congenital complete heart block (CCHB) is due to transplacental transfer of autoantibodies from mothers with connective tissue disease. Congenital heart block is usually complete, but incomplete blocks, sinus bradycardia and QTc prolongation are also reported. Anti SS A and Anti SS B antibodies transferred from mothers have inflammatory and arrhythmogenic effects in the fetal conduction system. Cardiac manifestations reported include dilated cardiomyopathy, endocardial fibroelastosis and mitral insufficiency. Low ventricular rate, QT prolongation and arrhythmias on monitoring are high risk features. CCHB has a mortality of 30%, and 60% of infants require pacemaker therapy. Fetal echocardiography is useful in early diagnosis. Prophylactic steroid therapy is controversial. Beta adrenergic agonists were tried in mothers with fetuses having congenital heart block to increase fetal heart rate. Early pacemaker therapy is indicated in patients with symptomatic bradycardia and ventricular dysfunction. The indications for pacing in congenital heart block continue to evolve with advances in techniques and most of these children will ultimately require permanent pacemakers by adulthood.

Fetal echocardiographic evaluation of atrial morphology and the prediction of laterality in cases of heterotaxy syndromes

OBJECTIVE

To evaluate whether abnormal atrial morphology, which is well recognized in autopsy series, is detectable by fetal echocardiographic examination of the four-chamber view, and can therefore be utilized to differentiate left from right isomerism in heterotaxy syndromes.

METHODS

This study was a retrospective review of 30 cases with prenatally diagnosed heterotaxy syndromes. Ultrasound video recordings and still images were reviewed with respect to atrial morphology in the four-chamber view. In 25 cases the morphology of both atria was sufficiently well visualized on the recordings to be evaluated and only these were included in the study.

RESULTS

Two types of atrial morphology were distinguished in our cohort: a sickle-shape with the tip pointing laterally and apically, and a blunt shape resembling the usual atrial appearance in the four-chamber view. Nineteen out of the 25 cases (76%) presented with isomerism of the atria in the four-chamber view. Thirteen had bilateral sickle-shaped atrial morphology, all associated with left isomerism. Six had bilateral blunt-shaped atrial morphology, all associated with right isomerism. The atria of the remaining six cases were not isomeric, the right atrium being sickle-shaped and the left blunt-shaped. Five of the latter cases were associated with left and one with right isomerism.

CONCLUSIONS

The majority of prenatally diagnosed heterotaxy syndromes seem to present with isomeric atrial morphology in the four-chamber view. In these cases a differentiation between left and right isomerism can be based on the two distinct types of atrial morphology. This may further enhance the prenatal differentiation of these syndromes.