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.     

胎儿心律失常的超声心动图检测及其临床意义

目的 探讨超声心动图检测对胎儿心律失常的诊断价值及临床意义。方法 采用超声心动图对725例胎龄16-41周临床疑诊为心律失常或存在其他异常的胎儿进行检测。结果 共检出胎儿心律失常90例。其中,期前收缩72例(房性期前收缩65例,室性期前收缩7例),心动过缓9例,心动过速6例,2:1房室传导阻滞2例,心房扑动1例。4例心动过缓胎儿并发先天性心血管畸形患者,2例在随访过程中死于宫内(尸体解剖证实为单心室伴肺动脉瓣狭窄1例,心脏横纹肌瘤1例),2例终止妊娠(尸体解剖证实为二尖瓣闭锁1例,共同房室通道1例)。1例胎龄38周心房扑动胎儿经吸氧及严密监护24h后,心律失常无缓解,立即行剖宫产术,出生后应用西地兰后心律转为窦性。其余85例胎儿心律失常均为阵发性,不伴有胎儿心脏形态、结构畸形及胎儿水肿,均足月出生,出生后听诊均未闻及心脏杂音及心律失常。结论 胎儿超声心动图是产前检查胎儿心律失常的可靠的无创性影像技术,其应用有助于早期检出并指导心律失常胎儿的处理。     

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.     

Disorders of laterality and heterotaxy in the foetus

Disorders of laterality and heterotaxy syndromes are rare diseases with an incidence of 1-1.5/10,000 live births. They are associated with numerous viscerocardiac anomalies and malformations. In particular, heterotaxy syndromes are associated with complex cardiac and extracardiac malformations that have an important impact on the prenatal and postnatal course. A prenatal differentiation between the 2 main variants of heterotaxy--left and right isomerism--is possible by assessment of cardiac rhythm, anomalies of caval veins and descending aorta and concomittant cardiac and extracardiac anomalies. An exact diagnosis is mandatory for adequate counselling of the parents and planning of postnatal care. Left isomerism has a high intrauterine mortality, caused by early atrioventricular block with subsequent cardiac failure and hydrops. In contrast, right isomerism has a high postnatal mortality due to the more complex type of cardiac defects and splenic disorders. The type of associated cardiac and extracardiac anomalies determines the postnatal morbidity and mortality. Polysplenia and asplenia may be associated with immunological disorders, that cannot be ruled out in the prenatal period, and further complicate the postnatal course.     

Arrhythmias in perinatal period and neonatal outcome--analysis of own experiences

OBJECTIVE: The paper presents review of different kinds of fetal arrhythmias, diagnosed in our centres. DESIGN: The aim of our study was to analyse results of echocardiographic examinations of 141 fetuses with diagnosed arrhythmias referred for fetal cardiac examination in years VI. 1996-V. 2001 and neonatal outcome. RESULTS: Premature contractions were recognised in 113 (80%) fetuses, tachyarrhythmias in 7 (5%) cases and complete atrioventricular block in 5 (4%). Heart defects were diagnosed in three cases. Three fetuses developed congestive heart failure (2x SVT, 1x HLHS + block a-v III*). From all group 6 newborns died. CONCLUSION: In case of fetal arrhythmias echocardiography should be widely applied in order to evaluate the kind of arrhythmia, sufficiency of circulation and coexistence of heart defects or functional abnormalities with arrhythmia in fetal circulation.     

Quantitative analysis of cardiac function in non-immunological hydrops fetalis

The present study was designed to quantitatively evaluate fetal cardiac dysfunction in fetal congestive heart failure associated with cardiogenic hydrops fetalis. Thirty-seven cases of non-immunological hydrops fetalis and/or fetal heart disease were assigned to four groups: (1) hydrops fetalis with structural heart disease; (2) hydrops fetalis without heart disease; (3) structural heart diseases without hydrops, and (4) complete A-V block without hydrops. One hundred and ten control fetuses were also studied. The ejection fraction in the first and third groups was significantly lower than that in the control. In the first group, systolic flow velocity in the descending aorta normalized but gestational age was significantly lower than that in the controls. Compensation of fetal cardiac function in the fourth group (complete A-V block) was noted on the basis of higher flow velocity and higher contractility. The cardiothoracic area ratios of the pathological and control groups were also evaluated.     

Outcome for fetuses with prenatally detected congenital heart disease and cardiac arrhythmias in Taiwan.

BACKGROUND/PURPOSE: Outcome for fetuses with prenatally detected congenital heart disease (CHD) and/or cardiac arrhythmias is important for prenatal counseling and perinatal management; however, there exists little literature regarding the outcome for CHD diagnosed in utero in Taiwan. Therefore, we attempted to investigate the outcome for fetuses with CHD and/or cardiac arrhythmias diagnosed prenatally at a tertiary care medical center in Taiwan. METHODS: Between January 1995 and December 2000, 339 patients referred to the National Taiwan University Hospital for fetal echocardiography were included in this study. Medical records were reviewed retrospectively to determine the salient clinical characteristics for all fetuses. RESULTS: CHD was found in 103 fetuses. Gestational age at diagnosis ranged from 17 to 40 weeks; in 37 cases (35.9%) the diagnosis was made before 24 weeks. Mean gestational age at diagnosis was 27.8 weeks. Of the 103 cases, 15 fetuses (14.6%) had major extra cardiac malformations and 15 fetuses (14.6%) had chromosomal abnormalities (five had both) and 30 pregnancies (29.1%) were terminated. Of the remaining 73 pregnancies, three (4.1%) of the fetuses died in utero and 28 (38.4%) postnatally, with 42 (57.5%) surviving. The mortality rates were both 60% in cases with extracardiac or chromosomal anomalies. Arrhythmias were identified in 25, and two pregnancies involving hydrops fetalis were terminated. Of the remaining 23 continued pregnancies, two (8.7%) with long QT syndrome expired postnatally. CONCLUSION: Outcome for fetuses with prenatally detected CHD remains poor, with the prognosis negatively influenced by the presence of complex heart defects as well as extracardiac and chromosomal anomalies. However, prognosis is good for fetuses with cardiac arrhythmia, except with long QT syndrome or hydrops fetalis.     

Fetale Heterotaxie-Syndrome

The spectrum of conditions associated with heterotaxy syndromes includes a wide variety of cardiovascular and visceral anomalies that are differently distributed amongst the two clinical variants, left and right isomerism, and which determine the intrauterine as well as the postnatal course and outcome. An exact prenatal diagnosis is therefore warranted. Important sonographic markers in heterotaxy syndromes are the associated anomalies of the situs and cardiac defects. Prenatal differentiation of the two clinical variants can be based on the anomalies, the course of the inferior vena cava and the presence of a heart block.In left isomerism, mortality is highest in the prenatal period due to frequent association with a complete heart block and subsequent intrauterine heart failure. In the postnatal period, the outcome depends mainly on the associated cardiac malformations and their ability to be corrected.In contrast, in right isomerism the mortality is highest in the postnatal period. This is mainly due to the more complex type of associated cardiac malformations.     

Prenatally diagnosed fetal lung lesions with associated conotruncal heart defects: is there a genetic association?

Congenital lung malformation can easily be diagnosed by prenatal ultrasound. Associated extrapulmonary malformations such as heart defects and chromosomal aberrations are rare.OBJECTIVE: The objective of this study was to describe the natural history, outcome and other associated malformations in fetuses with lung lesions and an associated heart defect. METHODS: Retrospective analysis of 4 cases of prenatally diagnosed fetal CCAMs and hybrid lesions with an associated heart defect and review of 8 cases in the literature. RESULTS: At a single referral center 1.9% of the fetuses with Congenital cystic adenomatoid malformation (CCAM) were diagnosed with an associated heart defect. Seven of the total 12 cases (58%) reviewed had a conotruncal heart abnormality. Chromosomal abnormalities were found in 5 (42%) of the cases. CONCLUSION: This retrospective review shows that karyotyping in fetal lung lesions with an associated heart defect or isolated large lung lesions is indicated. It also suggests that there is a subpopulation of fetuses with CCAMs who have conotruncal heart defects. This finding may suggest a common genetic background.     

Prenatally evolving ectopia cordis with successful surgical treatment

Ectopia cordis (EC) is a rare malformation due to failure of maturation of the midline mesodermal components of the chest and abdomen. It can be defined as a complete or partial displacement of the heart outside the thoracic cavity. It comprises 0.1% of congenital heart diseases. Common cardiac anomalies associated with EC are ventricular septal defect, atrial septal defect, and tetralogy of Fallot. EC and additional anomalies usually lead to intrauterine death. The possibility and efficacy of surgery in a surviving neonate depends on the degree of EC, coexisting congenital heart defects and extracardiac malformations. We present a case of prenatally diagnosed isolated EC diagnosed in the first half of pregnancy. After counseling, the patient decided to continue her pregnancy which ended with a newborn baby discharged from the hospital after cardiac surgery performed just after elective cesarean section.     

产前超声诊断在胎儿左侧异构中的应用

目的:探讨胎儿左侧异构的产前超声征象及其诊断价值。方法:回顾分析21例产前诊断为胎儿左侧异构的病例资料,对比总结其超声征象与随访结果。结果:21例左侧异构胎儿中,内脏心脏异位16例,先天性心脏病19例(伴心脏传导阻滞5例),下腔静脉离断伴奇静脉异常连接19例,其中两种及两种以上异常诊断胎儿左侧异构的敏感性为90.5%。染色体异常3例,18三体2例,13三体1例。18例终止妊娠,1例胎死宫内,2例存活。结论:产前超声诊断胎儿左侧异构是可行的,重要超声征象是内脏心脏异位、先天性心脏病伴或不伴心脏传导阻滞、下腔静脉离断伴奇静脉异常连接,出现上述两种或两种以上异常可提高该病的诊断敏感性。     

Long-term outcome in fetuses with cardiac arrhythmias

OBJECTIVE: The objectives of this follow-up study of 292 fetuses with various cardiac arrhythmias were to estimate the incidence of structural heart defects and fetal compromise, to investigate the effects of antiarrhythmic medication, and to evaluate perinatal mortality and morbidity and long-term outcome. METHODS: The arrhythmias were classified into atrial extrasystoles (n = 200), atrial tachycardias (n = 35), atrioventricular block (n = 36), sinus bradycardia (n = 14), and ventricular extrasystoles (n = 7), and outcome of the infants was analyzed. RESULTS: The incidence of cardiac anomalies was 12% in the study population. In utero cardiac failure was noted in 11%. Among fetuses with atrial extrasystoles, 1% developed supraventricular tachycardia after birth. During antiarrhythmic therapy, sinus rhythm was achieved in 92% of nonhydropic and in 63% of hydropic fetuses. The latter had higher mortality and risk for neurologic morbidity than did nonhydropic fetuses; 38% versus 3.7% and 40% versus 12%, respectively. Among fetuses with atrioventricular block only, the survival rate was 82%, with a heart defect, prognosis was poor: 50% survived. Sinus bradycardia and ventricular extrasystoles were associated with survival rates of 75% and 67%. In the follow-up of the whole study population lasting a median 5 years, 93% are alive and 3% have a neurologic disorder. CONCLUSION: All fetal arrhythmias except atrial extrasystoles were associated with a moderately high risk for fetal distress. In cases of compromise, fetal and neonatal prognosis was poor and was an indication for perinatal medication. After the newborn period, the prognosis has been good. However, the risk for neurologic morbidity must be taken into consideration.     

Lymphangioma--prenatal and perinatal aspects--Part one

Lymphangioma or cystic hygroma is a congenital malformation of the lymphatic system which has been commonly associated with fetal aneuploidy, hydrops, structural malformations and intrauterine death. In this paper we would like to report two cases of lymphangioma diagnosed prenatally in the third trimester in the fetuses with normal karyotype, normal NT in the first trimester and without other structural anomalies and with good perinatal outcome.     

Ductus venosus blood flow velocity waveforms as a predictor for fetal outcome in isolated congenital heart disease

OBJECTIVE: To investigate whether pulsatility of ductus venosus (DV) flow velocity waveforms is of diagnostic value in predicting survival in fetuses with congenital heart disease (CHD). METHODS: In a cross-sectional study, Doppler investigation of DV and umbilical artery blood flow was performed in 58 fetuses with isolated structural CHD, without other sonographically detectable structural or chromosomal abnormalities or tachyarrhythmia. The pulsatility index for veins of DV (DV-PIV) waveforms was expressed as multiples of the 95th centile (Mo95th) of the reference ranges for gestational age. The PIV was related to intrauterine and neonatal mortality within the first 6 months of life. Terminations of pregnancies and neonates with additional abnormalities detected after birth were excluded from statistical analysis. For statistical analysis, the different types of heart defects were separated into atrial and/or ventricular (AV) septal defects, right or left ventricular in- and outflow tract abnormalities and others. RESULTS: After exclusion of 9 pregnancies (2 cases with failure of measurements of DV-PIV, 2 neonates with additional malformations, and 5 terminations of pregnancies), 49 cases were available for statistical analysis. The umbilical artery pulsatility index was within normal ranges in all but 1 case with AV canal and hydrops. In 7 pregnancies intrauterine fetal deaths occurred and 6 of them were hydropic. The median gestational age at birth for liveborn neonates was 39.0 weeks (range 27.8-41). There were 6 postnatal deaths, all but 1 within 28 days of delivery. The remaining fetuses survived for at least 6 months. The overall mortality rate was 27% (13/49). The DV-PIV was significantly higher in non-survivors than in survivors (median of Mo95th and interquartile ranges 1.48 (1.04-1.95) vs. 0.81 (0.70-1.15); p = 0.01). Analysis of subgroups showed significant differences for AV septal defects and abnormalities affecting predominantly the right ventricle (p = 0.046 and 0.043, respectively). Ten out of 13 non-survivors showed an abnormal DV-PIV (sensitivity 77%) as compared to 12 out of 36 survivors (specificity 67%). All hydropic fetuses (n = 6) showed an abnormal DV-PIV and ended in intrauterine deaths. CONCLUSIONS: Evaluation of the DV pulsatility is a useful additional variable for predicting the risk for mortality in fetuses with isolated structural CHD, in particular in fetuses with defects of the AV septum and with defects affecting predominantly right ventricular function. As there is no fetal hydrops without abnormal DV, this is another sign for the association of DV and cardiac failure.     

产前超声诊断胎儿右房异构一例

本文报道产前超声诊断胎儿右房异构一例。孕妇孕24周产前超声检查发现胎儿左位心合并复杂心血管畸形(右心室双出口、房室间隔缺损、肺动脉发育不良、双侧上腔静脉、心下型完全型肺静脉异位引流)、胃泡位于腹腔右侧、中位肝、可疑无脾、腹主动脉与下腔静脉位于脊柱左侧、双侧支气管呈右侧支气管对称形态,综合考虑右房异构可能。引产后经尸体解剖证实脾脏发育不良、右房异构。右房异构常合并复杂心血管畸形,因此产前超声发现复杂心血管畸形时,应警惕右房异构的可能。右房异构病死率极高,产前诊断具有重要意义。     

Prenatal diagnosis of asplenia/polysplenia syndrome

Complex congenital heart disease with atrioventricular block was detected prenatally in two fetuses at 34 and 28 weeks' gestation. The spleen was not seen on ultrasonographic examination in either fetus, suggesting polysplenia/asplenia syndrome. Both infants died shortly after delivery and the autopsies confirmed this diagnosis. Recommendations for sonographic screening of the fetal spleen in cases of prenatal detection of complex heart disease or cardiac dysrhythmia are discussed.     

胎儿先天性肺囊性腺瘤样畸形35例临床分析

目的探讨胎儿先天性肺囊性腺瘤样畸形(CCAM)的临床特点和预后。方法回顾性分析2004年2月至2009年7月在复旦大学附属妇产科医院经产前超声诊断为CCAM的35例胎儿的临床资料。超声监测CCAM病灶大小及并发症的变化。结果超声检查提示:Ⅰ型15例,Ⅱ型11例,Ⅲ型8例,Ⅰ型合并Ⅲ型1例。14例合并纵隔或心脏移位,3例合并羊水过多,3例合并颈部透明带增厚,1例合并脑积水,2例合并胎儿生长受限,1例合并胎儿腹水和水肿,1例合并羊水过多和消化道畸形。7例行羊水穿刺染色体检查,未发现异常核型。8例诊断后失访。27例随访病例中,1例伴有水肿和腹水的胎儿孕29周胎死宫内,11例孕妇终止妊娠,15例胎儿分娩。15例婴儿中,6例妊娠期间病灶消失,4例产后病灶消失,2例未消失,3例暂未随访。产后15例婴幼儿身体健康。结论胎儿水肿和腹水是胎儿预后不良的因素。如果胎儿未出现水肿、腹水,未合并其他畸形,胎儿CCAM预后良好,可继续妊娠。     

The significance and importance of prenatal diagnosis of fetal cardiac malformations by Doppler echocardiography

Pulsed Doppler echocardiography is an excellent technique for cardiac diagnosis and assessment of cardiac performance in combination with M-mode and two-dimensional echocardiography. Its exact role in fetal cardiac diagnosis has not been established. We examined 67 high-risk fetuses for cardiac malformations and found cardiac abnormalities or malfunction in 15. In four fetuses pulsed Doppler echocardiography played a primary or a definitive diagnostic role: One fetus had a complete atrioventricular canal, another lacked the pulmonary valve, the third had transposition of the great vessels without ventricular septal defect, and the fourth had high cardiac output failure caused by placental chorioangioma. Pulsed Doppler echocardiography is an integral part of the ultrasonic cardiac examination in high-risk fetuses and should be used in combination with two-dimensional and M-mode echocardiography. It has an important place in the diagnosis of high-risk fetuses and may have a primary role in the diagnosis of fetuses when ultrasound resolution is poor, where cardiac circulatory hemodynamics are essential for diagnosis, and in complicated cardiac malformations in which a comprehensive and accurate diagnosis can be achieved only with pulsed Doppler echocardiography.     

Isolated congenital atrioventricular block diagnosed in utero: Natural history and outcome

Background. Isolated congenital atrioventricular block (CAVB) diagnosed in utero is associated with a high morbidity and mortality. Prognosis is especially poor when heart rate drops below 55 beats per minute (bpm) and when fetal hydrops develops. We describe the natural history and outcome of 24 infants with isolated CAVB diagnosed in utero, review the literature, and assess the risk factors that could predict outcome.

Methods. This was a retrospective multicenter study of 24 patients with isolated CAVB diagnosed in utero.

Results. CAVB was detected at a mean gestational age (GA) of 24.7 ± 5.1 weeks. Ten fetuses initially presented with complete heart block. Low heart rate or incomplete heart block was the first documentation of bradyarrhythmia in the other 14 fetuses. In 11 of them, CAVB developed during pregnancy after a median time of 3 (range 1–16) weeks. Fetal hydrops developed in 10 of 24 (42%) fetuses at a mean GA of 27.6 ± 5.1 weeks. Hydropic fetuses showed lower heart rates during pregnancy (47 ± 10 bpm) than non-hydropic fetuses (57 ± 10 bpm). There were three intrauterine deaths; all were hydropic and female. Nine viable females and 12 males were born at a mean GA of 37.1 ± 6.1 weeks with an average birth weight of 3097 ± 852 g. Fifteen CAVB patients required pacemaker (PM) intervention, 10 of them immediately after birth. Dilated cardiomyopathy (DCM) developed in three infants of whom two died of congestive heart failure, shortly after the diagnosis was made; one is still alive. Mortality before or after birth was 21%, and was associated with heart rates below 50 bpm and development of fetal hydrops. Poor outcome, defined as death, PM implantation, or development of DCM, occurred in 83% of cases and was associated with heart rates below 60 bpm during pregnancy.

Conclusions. Isolated CAVB diagnosed in utero is associated with high morbidity and mortality. Patients who develop fetal hydrops show lower heart rates during pregnancy than patients who do not. A fetal heart rate below 50 bpm and development of fetal hydrops is associated with increased mortality. Rates below 60 bpm are associated with PM requirement and/or DCM.