Fetal complete heart block: antenatal diagnosis, significance and management

Complete heart block was diagnosed prenatally in 21 fetuses. Associated structural cardiac defects were present in 18 fetuses, in particular complete atrioventricular canal with atrial isomerism (5 cases), and 'corrected' transposition of the great arteries (4 cases). Maternal systemic lupus erythematosus was proved in only one case. In 11 fetuses, intra-uterine congestive heart failure with the signs of non-immune hydrops fetalis occurred. In all 11 fetuses, the hydrops was associated with a cardiac defect, in particular complete atrioventricular canal with atrial isomerism in 5 cases. A review of the literature confirms that only the association of complete heart block and cardiac malformation can cause intra-uterine congestive heart failure, whereas in the case of fetal complete heart block without cardiac malformation or with prenatally hemodynamically insignificant cardiac malformation, congestive heart failure is rare. Only 30% of newborns with complete heart block have associated cardiac malformations. In our series, however, 86% of the fetuses with complete heart block had cardiac malformations. The most important reason for this percentage discrepancy is that almost all fetuses with associated severe cardiac defects, in particular atrioventricular canal defects, develop heart failure which frequently results in prenatal death. Thus, fetal deaths are not included in pediatric statistics. Nevertheless, fetuses with isolated complete heart block generally do not develop heart failure and in almost all of the cases are born alive.     

In utero treatment of fetal complete heart block with terbutaline. A case report.

BACKGROUND: Isolated fetal complete heart block is an uncommon finding, with a mortality rate of 20-30%. Various treatment modalities have been reported, with no consistent success. CASE: Fetal complete heart bock was diagnosed in a 30-year-old woman at 29 weeks' gestation. She had an elevated antinuclear antibody and anti-SSA antibody titer. Fetal cardiac decompensation was detected at 32 weeks. After a trial of intravenous isoproterenol without significant side effects, she was treated with oral terbutaline. An increase in the fetal ventricular rate and complete resolution of hydrops fetalis occurred. A male infant was delivered by cesarean section, at term, and underwent cardiac pacemaker implantation at 4 days of age. CONCLUSION: The treatment of fetal complete heart block is controversial. Premature delivery with cardiac pacing is associated with high morbidity and mortality. We report prenatal treatment with oral sympathomimetic medication, which allowed delivery to be delayed until term, with a successful outcome.     

Evaluation of the preload condition of the fetus by inferior vena caval blood flow pattern

Using pulsed Doppler ultrasound, blood flow in the inferior vena cava (IVC) was studied in 47 normal fetuses from 24 to 40 weeks of gestation and 35 abnormal fetuses, with the exception of those with arrhythmias. The abnormal fetuses were divided into 4 groups according to diagnosis, i.e., 6 cases of heart disease with hydrops (group 1), 9 cases of heart disease without hydrops (group 2), 11 cases of hydrops without heart disease (group 3), and 9 cases of other fetal diseases (group 4). By measuring the velocity of IVC blood flow, we defined a new index, the change in parallel with reverse flow velocity, and called it the preload index (PLI). In normal fetuses, PLI values ranged from 0 to 0.37 and had no relation with gestational age. The PLI was significantly higher in groups 1-3 than in normal fetuses. In group 1, the PLI was also higher than in group 2. In group 3, the PLI values in 4 cases of chylothorax, 1 of chyloascites and 1 of cytomegalovirus infection were significantly lower than in the remaining 5 cases where the cause of hydrops was undetermined. The PLI was normal in 9 fetuses with other diseases and no hydrops. The PLI was increased in conditions in which excessive preload, tricuspid regurgitation, or some kind of structural heart disease were present.     

The resolution of fetal hydrops using combined maternal digoxin and dexamethasone therapy in a case of isolated complete heart block at 30 weeks gestation

The development of hydrops fetalis in cases of isolated complete heart block is associated with a very poor prognosis. Various pharmacological strategies have been proposed, involving both direct fetal access and transplacental therapy, with inconsistent results in small numbers of subjects. The optimal antenatal management will remain uncertain until multicentre controlled trials are organised. We report the complete resolution of fetal hydrops at 30 weeks of gestation using combination of maternal digoxin and dexamethasone therapy, despite persistence of the complete heart block. A Caesarean section was performed at 37 weeks of gestation due to evidence of fetal intrauterine growth restriction. The baby girl is now 8 months of age and remains well, with a heart rate of 45-50 beats per minute on no medication and without pacing.     

Fetal bradycardia in the first trimester: an unusual presentation of atrial extrasystoles

We report a fetus with fetal bradycardia at 13 weeks of gestation secondary to atrial extrasystoles. The fetus subsequently developed paroxysmal supraventricular tachycardia and hydrops fetalis. The cardiac arrhythmia recovered spontaneously without any medical intervention. This case illustrates that atrial ectopic beats can present in the first trimester with fetal bradycardia. Rapidly evolving hydrops fetalis secondary to supraventricular tachycardia can develop, warranting close monitoring with weekly heart rate assessment. Fetal bradycardia secondary to atrial extrasystole should be differentiated from first trimester sinus bradycardia and those associated with major structural cardiac abnormality, which have a high fetal loss rate.     

Transient non-autoimmune fetal heart block

OBJECTIVES: Fetal heart block is a rare and irreversible condition associated with structural heart defects or maternal autoantibodies (SS-A/Ro and SS-B/La) resulting in permanent damage of the atrioventricular (AV) node. This is the first report of 4 cases with a transient fetal heart block in structurally normal hearts without maternal autoantibodies. METHODS: A report on 4 patients seen within a 14-year period at one center with fetal heart block without intracardiac abnormalities or maternal autoantibodies. RESULTS: Three patients were referred to our center with a fetal bradycardia (heart rate 70-85 bpm), between 20 and 33 weeks' gestational age, and 1 for a 'triple' test at 16 weeks' gestational age. Echocardiography showed a complete heart block in 2 fetuses, and a second-degree AV block in the other 2. Heart block had completely resolved at all following visits. Postnatal ECG recordings showed normal sinus rhythm in all patients. Echocardiographic evaluation at presentation and follow-up showed normal cardiac anatomy, without signs of hydrops or cardiac decompensation in all patients. All mothers tested negative on SS-A/Ro and SS-B/La autoantibodies. CONCLUSIONS: Fetal heart block can occur in the absence of structural heart defects and maternal autoantibodies to SS-A/Ro and SS-B/La. The origin of such heart block is unknown, but its course seems benign: none of the patients ever showed ventricular heart rates <55 bpm, signs of congestive heart failure or fetal hydrops. Heart block resolved spontaneously in all patients.     

Aetiology of non-immune hydrops: the value of echocardiography

Forty-eight pregnancies, five of them multiple, were referred for fetal cardiac assessment following the detection of non-immune hydrops fetalis; there were 52 hydropic fetuses in total. A cardiovascular aetiology was found in 21 of these 52 (40%); structural heart disease was present in 13, tachyarrhythmia in the remaining eight. The accurate delineation of these causes was possible using fetal echocardiography, and enabled rational management to be instituted. This included termination of pregnancy, pharmacological control of arrhythmias and appropriate timing of delivery.     

Aetiology of non-immune hydrops: the value of echocardiography

Summary. Forty-eight pregnancies, five of them multiple, were referred for fetal cardiac assessment following the detection of non-immune hydrops fetalis; there were 52 hydropic fetuses in total. A cardiovascular aetiology was found in 21 of these 52 (40%); structural heart disease was present in 13, tachyarrhythmia in the remaining eight. The accurate delineation of these causes was possible using fetal echo-cardiography, and enabled rational management to be instituted. This included termination of pregnancy, pharmacological control of arrhythmias and appropriate timing of delivery.     

Etiology and outcome of hydrops fetalis.

OBJECTIVES: To identify the etiology and pregnancy outcome of hydrops fetalis in a cohort of pregnancies referred to a tertiary maternal fetal medicine center in the UK. These data allow the review of a large series of pregnancies affected by hydrops fetalis and emphasize the importance of investigation and then treatment of individual cases. This provides parents with improved information and especially specific prognostic information. METHODS: A retrospective review of 63 consecutive cases of hydrops fetalis managed between September 1996 and March 1999. RESULTS: Of the pregnancies, 12.7% (n = 8) were associated with an 'immune' etiology. Of these, 62.5% (n = 5) had fetal anemia due to anti-D, 25% (n = 2) anti-Kell and 12.5% (n = 1) anti-c antibodies. The remaining 55 cases (87.3%) had a non-immune cause. Eight (14.5%) were due to human parvovirus B19 infection. Fourteen cases (25.5%) were associated with aneuploidy and, in four (7.3%), a primary hydrothorax was the cause of the non-immune hydrops fetalis. A cardiac cause was found in five (9.1%) cases. Three of these had supraventricular tachycardia and one had congenital complete heart block. Cystic hygroma was associated with hydrops fetalis in six cases. Twin-twin transfusion syndrome was the cause for hydrops in two cases. Massive transplacental hemorrhage was identified in one case. Fetal akinesia and muscular dystrophy caused hydrops in one case each. In 14.5% (8/55) of cases no obvious cause was identified and these were classified as 'idiopathic'. Three other cases could not be classified because parents declined investigations (unclassified). In the pregnancies with non-immune hydrops fetalis, the outcome was favorable in 27.3% (15/55) of cases. CONCLUSION: The prognosis of hydrops fetalis differs markedly between different etiological groups. Etiologies range from treatable causes with a good outcome and probably no long-term side-effects (as in case of parvovirus B19), to others which are incompatible with life or are associated with considerable perinatal morbidity and mortality.     

Fetal hemoglobin Bart’s hydrops fetalis: pathophysiology,prenatal diagnosis and possibility of intrauterine treatment

This review aimed at comprehensively summarizing current available reports regarding the ultrasound markers and biomarkers in predicting fetal Hb Bart’s disease and evaluate the potential role of cardiac function assessment in a clinical practice. This review involves various methods in prenatal predicting fetal Hb Bart’s disease or alpha-thalassemia major and attempts to provide valuable insights regarding the underlying mechanisms responsible for heart failure in Hb Bart’s fetuses. Moreover, this information may be used to predict the cardiac function before the development of hydrops fetalis. Finally, the affected Hb Bart’s fetus could be the best model of the study on cardiovascular response to fetal anemia, thus the cardiovascular ultrasound and molecular assessment may be helpful in predicting the prognosis or in making a choice in the management of the fetal anemia condition. In conclusion, ultrasound findings especially cardiomegaly and an increase in peak systolic velocity of the middle cerebral artery (MCA-PSV) are helpful in predicting the future hydrops fetalis and ultrasound assessment of fetal cardiac function is potentially helpful in clinical practice. Finally, this review highlights the pathogenesis of hydropic changes secondary to fetal anemia.     

Outcome of fetal cystic hygroma and experience of intrauterine treatment

OBJECTIVE: To review our cases of fetal cystic hygroma and to examine the prognostic factors with the goal of establishing criteria for the intrauterine treatment for cystic hygroma. PATIENTS AND METHODS: Thirty-one cases of fetal cystic hygroma were managed by us from January 1988 to December 1997, and 21 cases were available for analysis. Three prognostic factors, namely chromosomal abnormality, structural anomaly and hydrops fetalis, were evaluated. We treated 2 cases of cystic hygroma associated with hydrops fetalis in utero using OK-432 injection under ultrasound guidance. RESULTS: The fetuses without any of the prognostic factors listed above showed a good prognosis throughout the fetal and neonatal periods. However, in this group, 2 infants with large tumors died of hemorrhage from the tumor at 6 months and 3 years of age, respectively. Cases with hydrops fetalis without chromosomal abnormalities or structural anomalies (5 cases) resulted in either intrauterine fetal death (IUFD, 2 cases) or early perinatal neonatal death (early PND, 3 cases). The cause of early PND was circulatory failure. Most of the hydrops cases with either a chromosomal abnormality or structural anomaly resulted in IUFD before 22 weeks of gestation. The size of the cyst decreased in 1 of 2 cases treated in utero. CONCLUSIONS: The fetal cases of cystic hygroma showing hydrops fetalis without chromosomal abnormalities or structural anomalies are considered to be possible candidates for intrauterine therapy. Those with very large cystic hygroma without any of the three prognostic factors are also thought to be candidates for fetal treatment. Based on our clinical experience, sclerotherapy using OK-432 is considered to be a treatment option in selected cases with fetal cystic hygroma.     

Etiology and outcome of hydrops fetalis

Objectives : To identify the etiology and pregnancy outcome of hydrops fetalis in a cohort of pregnancies referred to a tertiary maternal fetal medicine center in the UK. These data allow the review of a large series of pregnancies affected by hydrops fetalis and emphasize the importance of investigation and then treatment of individual cases. This provides parents with improved information and especially specific prognostic information. Methods : A retrospective review of 63 consecutive cases of hydrops fetalis managed between September 1996 and March 1999. Results : Of the pregnancies, 12.7% ( n = 8) were associated with an 'immune' etiology. Of these, 62.5% ( n = 5) had fetal anemia due to anti-D, 25% ( n = 2) anti-Kell and 12.5% ( n = 1) anti-c antibodies. The remaining 55 cases (87.3%) had a non-immune cause. Eight (14.5%) were due to human parvovirus B19 infection. Fourteen cases (25.5%) were associated with aneuploidy and, in four (7.3%), a primary hydrothorax was the cause of the non-immune hydrops fetalis. A cardiac cause was found in five (9.1%) cases. Three of these had supraventricular tachycardia and one had congenital complete heart block. Cystic hygroma was associated with hydrops fetalis in six cases. Twin-twin transfusion syndrome was the cause for hydrops in two cases. Massive transplacental hemorrhage was identified in one case. Fetal akinesia and muscular dystrophy caused hydrops in one case each. In 14.5% (8/55) of cases no obvious cause was identified and these were classified as 'idiopathic'. Three other cases could not be classified because parents declined investigations (unclassified). In the pregnancies with non-immune hydrops fetalis, the outcome was favorable in 27.3% (15/55) of cases. Conclusion : The prognosis of hydrops fetalis differs markedly between different etiological groups. Etiologies range from treatable causes with a good outcome and probably no long-term side-effects (as in case of parvovirus B19), to others which are incompatible with life or are associated with considerable perinatal morbidity and mortality.     

与Hb Bart’s水肿胎相关镜像综合征母体并发症的病例对照研究

目的:评价Hb Bart’s水肿胎(即α-地中海贫血1纯合子)是否并发镜像综合征和分娩孕周对母体并发症的影响。方法:回顾性分析Hb Bart’s水肿胎并发镜像综合征13例(A组)、Hb Bart’s水肿胎未并发镜像综合征61例(B组)和排除Bart’s水肿胎和血红蛋白H病(HbH)、无产科合并症的孕妇74例(C组)临床资料,对3组的实验室检查结果和母体并发症情况进行比较。另外,将74例Hb Bart’s水肿胎按照分娩孕周是否大于28周分成两个亚组,比较两亚组母体的发病情况。结果:①A组血细胞比容、血红蛋白、血小板和血清白蛋白均明显低于B、C组(P<0.05),尿酸明显高于B、C组(P<0.05);而B组和C组以上指标比较,差异均无统计学意义(P>0.05)。②A组母体严重并发症(包括弥漫性凝血功能障碍、心力衰竭、急性肺水肿、急性肾功能衰竭和HELLP综合征)、胎盘早剥、产后出血、肝肾功能损害和胎盘粘连的发生率均明显高于B组和C组(P<0.0167)。B组与C组比较,上述并发症发生率除产后出血和胎盘粘连外,其余均无统计学意义(P>0.05)。③74例Hb Bart’s水肿胎患者中,≥孕28周者,其有镜像综合征、母体有严重并发症、胎盘早剥、产后出血、肝肾功能损害和胎盘粘连的发生率均明显高于<孕28周组(P<0.05)。结论:Hb Bart’s水肿胎增加母体并发症的发生,其对母体的危害程度除了与是否并发镜像综合征有关,分娩孕周也是重要因素,临床上应重视Hb Bart’s水肿胎的早期产前诊断,一旦确诊应尽早终止妊娠,尽可能降低母体风险。     

Umbilical venous pressure in nonimmune hydrops fetalis: correlation with cardiac size.

OBJECTIVES: Our objectives were to examine the relationship between umbilical venous pressure and cardiac size in nonimmune hydrops fetalis and to assess the role of cardiac failure in the pathogenesis of the disease. STUDY DESIGN: Fourteen fetuses with nonimmune hydrops fetalis were investigated in a tertiary referral unit with high-resolution ultrasonography, echocardiography, and fetal blood sampling. Fetal heart size was assessed by measurement of the cardiothoracic ratio. Umbilical venous pressure was measured at the time of fetal blood sampling with a fluid-filled system. RESULTS: The 10 fetuses with elevated umbilical venous pressures had significantly increased cardiothoracic ratios (p = 0.02). These fetuses also had ascites. Four other fetuses had normal-sized hearts, normal umbilical venous pressures, and no ascites. There was a linear relationship between cardiothoracic ratio and umbilical venous pressure (r = 0.75, p = 0.003). CONCLUSION: Measurement of umbilical venous pressure validates cardiothoracic ratio as a noninvasive assessment of cardiac function in nonimmune hydrops.     

Prenatal diagnosis and management for a large fetal cardiac tumor complicated with hydrops fetalis

Fetal cardiac tumor is a rare disease, and its prognosis varies in relation to the complications such as arrhythmia and out-flow obstruction. Hydrops fetalis is one of severe complications that result in an unfavorable outcome. A case is presented herein of a large fetal cardiac tumor diagnosed at 28 weeks gestation. At 30 weeks gestation, the fetus complicated with hydrops fetalis because of impaired cardiac function. Increased peak systolic velocity in the ascending aorta and marked reversed flow in the ductus venosus were observed. Oral digoxin therapy was administered to the mother as a cardiotonic agent and the hydropic condition was immediately diminished. After normal delivery, the cardiac tumor gradually decreased in size and the infant developed normally, but required an antiarrhythmic drug. The case indicates that the in utero digoxin therapy could be a choice for hydrops fetalis caused by cardiac tumor.     

Investigation of nonimmune hydrops fetalis

Fifty pregnancies complicated by fetal ascites and generalized edema are reviewed and their prenatal findings, obstetric management, and fetal outcome are discussed. From the myriad of maternal, fetal, and placental problems which are known to cause nonimmune hydrops fetalis, many different causes of the disorder could be identified in 84% of all patients studied by extensive prenatal and postnatal workup. Therefore, in only 16% of the cases was the nonimmune hydrops fetalis labeled "idiopathic." The most common demonstrable causes of the disorder in this series were cardiac anomalies, followed by chromosomal disorders, congenital malformations, alpha-thalassemia, and the twin-twin transfusion syndrome. A systematic approach to the prenatal diagnostic workup of nonimmune hydrops fetalis is outlined, starting with the least invasive techniques (ultrasound, echocardiography, complete blood count, Kleihauer-Betke analysis, TORCH testing, and so forth) followed by more invasive techniques (amniocentesis and fetoscopy). Although the detection and prognostic evaluation of nonimmune hydrops fetalis are greatly improved by applying these techniques, the overall prognosis for most fetuses with nonimmune hydrops fetalis is still very poor, and only a few conditions causing the disorder, such as prenatally detected cardiac arrhythmias or selected cases of urinary tract obstruction, are amenable to treatment in utero.     

Early prenatal management of a fetal ventricular tachycardia treated in utero by amiodarone with long term follow-up

Fetal cardiac arrhythmias are one of the causes of intra-uterine congestive heart failure and non-immune hydrops fetalis leading to fetal death. As ventricular tachycardia (VT) is rarely diagnosed in utero, it leads to emergency deliveries. We report a prenatal diagnosis of fetal tachycardia at 20 weeks of gestation associated with non-immune hydrops fetalis. The tachycardia seemed to be supraventricular and was initially treated by digoxin and sotalol. The hydrops increased and sotalol was stopped in order to give the mother a high dose of amiodarone by mouth over a long period. Although the tachycardia, which the ECG recorded at birth revealed to be of ventricular origin, persisted but at a lower rate, the new treatment proved successful. The child is three years old now and health, though with persistent VT. In conclusion, fetal tachycardia with similar ventricular and atrial rates can be a VT and the drug of choice in this case seems to be amiodarone.     

Rhesus disease and non-immune hydrops

Hippocrates first documented the condition of ‘fetal hydrops’ in 400 BC. There was recognition of jaundice of the newborn in the 17th century, but it was not until 1909 that Buchan established a link between some cases of newborn jaundice and anaemia, and 1932 before Diamond described the condition of erythroblastosis fetalis.Between 1938 and 1941, the identification of maternal red cell antibodies, the Rhesus antigen and blood group inheritance were established. In 1947, Diamond first described post-natal treatment utilizing transfusion, with exchange transfusion being described by Mollison in 1952. Intra-uterine therapy was not established until 1963 when Liley first published the use of intraperitoneal transfusion.The last 40 years have seen rapid advances in the understanding, assessment and therapy of Rhesus disease and non-immune hydrops. We have seen exploration of: amniotic fluid bilirubin levels, to determine whether a fetus is at risk of haemolytic disease of the newborn (Freda and Liley); plasmapheresis (Powell), aiming to reduce the maternal circulating antibody levels; fetal blood sampling, to establish a diagnosis; and intraperitoneal or intravascular transfusion, as methods of direct therapy, the latter initially using fetoscopy and then using an ultrasound-guided approach to fetal vessels.Stem-cell therapy has been explored and, more recently, non-invasive methods to assess fetal anaemia have been introduced using the mean range on a computerized cardiotocograph (CTG) and middle cerebral artery maximum flow velocity. In cases where the partner is heterozygous for a particular red cell antigen, the potential for determining fetal group by identification of fetal cells in the maternal circulation for testing has also become a possibility.Approximately 20% of cases of non-immune hydrops remain ‘idiopathic’, the remainder either being a result of a cardiac structural anomaly, arrhythmia or a metabolic disorder. Twinning accounts for approximately 6% of cases of non-immune hydrops.This article aims to give an overview of what is happening today and a glimpse of what might be possible in the future.     

Use of a subcutaneous beta-sympathomimetic pump for the treatment of fetal congenital complete heart block. A case report

BACKGROUND: Complete heart block is the most common congenital heart block diagnosed in the fetalneonatal period. Maternal administration of beta-sympathomimetic agents has been used to treat this condition in the fetus. We know of no previous reports of the delivery of beta-sympathomimetics via a continuous subcutaneous pump for management of this condition. CASE: An intrauterine gestation at 28 5/7 weeks complicated by fetal congenital complete heart block was successfully managed to term with maternal administration of a beta-sympathomimetic agent via a continuous subcutaneous pump. CONCLUSION: Maternal administration of beta-sympathomimetic agents by a continuous subcutaneous pump in cases of fetal congenital complete heart block may help prolong pregnancy by preventing hydrops fetalis and avoiding confounding problems of prematurity. However, it should be used with caution due to the potential for dilated cardiomyopathy in the infant.