Diagnosis of heterotaxy syndrome by fetal echocardiography

Limitations and opportunities in the pharmacotherapy of ciliopathies

Ciliopathies are a family of rather diverse conditions, which have been grouped based on the finding of altered or dysfunctional cilia, potentially motile, small cellular antennae extending from the surface of postmitotic cells. Cilia-related disorders include embryonically arising conditions such as Joubert, Usher or Kartagener syndrome, but also afflictions with a postnatal or even adult onset phenotype, i.e. autosomal dominant polycystic kidney disease. The majority of ciliopathies are syndromic rather than affecting only a single organ due to cilia being found on almost any cell in the human body. Overall ciliopathies are considered rare diseases. Despite that, pharmacological research and the strive to help these patients has led to enormous therapeutic advances in the last decade. In this review we discuss new treatment options for certain ciliopathies, give an outlook on promising future therapeutic strategies, but also highlight the limitations in the development of therapeutic approaches of ciliopathies.

Novel insights into the genetic landscape of congenital heart disease with systems genetics

We recently conducted a large-scale mouse mutagenesis screen and uncovered a central role for cilia in the pathogenesis of congenital heart disease (CHD). Though our screen was phenotype based, most of the genes recovered were cilia-related, including genes encoding proteins important for ciliogenesis, cilia-transduced cell signaling, and vesicular trafficking. Also unexpected, many of the cilia related genes recovered are known direct protein-protein interactors, even though each gene was recovered independently in unrelated mouse lines. These findings suggest a cilia-based protein-protein interactome network may provide the context for congenital heart disease pathogenesis. This could explain the incomplete penetrance and variable expressivity of human CHD, and account for its complex non-Mendelian etiology. Supporting these findings in mice, a preponderance of cilia and cilia related cell signaling genes were observed among de novo pathogenic variants identified in a CHD patient cohort. Further clinical relevance unfolded with the observation of a high prevalence of respiratory cilia dysfunction in CHD patients. This was associated with increased postsurgical respiratory complications. Together these findings highlight the importance of cilia in CHD pathogenesis and suggest possible clinical translation with instituting pulmonary therapy to improve outcome for CHD patients undergoing congenital cardiac surgeries.

Pre natal evaluation of heterotaxy syndrome by fetal echocardiography and correlating with autopsy

Introduction

Heterotaxy syndrome/ isomerism is characterized by an abnormal symmetry of the viscera that are normally dissimilar due to abnormal lateralization of thoracic and abdominal viscera and is frequently associated with complex cardiac anomalies. Isomerism may be of right or left.

Materials and methods

This article describes the morphological characteristics of heterotaxy and suggests an approach in evaluating the spectrum of abnormalities associated with this syndrome. This study is based on 12 cases diagnosed on antenatal ultrasound as heterotaxy syndrome. Results of the examinations were re-evaluated and compared by fetal autopsy.

Result

Based on the following echocardiographic criteria, a diagnosis of left isomerism was made if there was viscerocardiac heterotaxy associated with an interruption of inferior vena cava or with bilateral finger-like atrial appendages or if it was associated with heart block. If there was evidence of viscerocardiac heterotaxy with complex cardiac anomalies then it was diagnosed as right atrial isomerism or visceral heterotaxy syndrome. We diagnosed 6/12 as left isomerism and rest of the cases as right isomerism/visceral heterotaxy syndrome. In Autopsy we evaluated visceral situs and morphology of the lungs and the main bronchi, the state of the liver, spleen, bowel, and the precise anatomy of the heart and confirmed 4/12 as left isomerism 4/12 as right isomerism and two cases as visceral heterotaxy syndrome (VHS). Rest of the two cases were included in the study despite missing autopsy data, as the combination of abnormal situs with interrupted inferior vena cava, and cardiac malformation allowed a diagnosis of left isomerism with high probability.

Conclusion

In this study, we aimed to find common features of heterotaxy syndrome on prenatal ultrasound as well as on fetal autopsy. This syndrome should be accurately diagnosed in the prenatal period in order to allow appropriate counseling of parents.

Outcome of prenatally diagnosed fetal heterotaxy: systematic review and meta-analysis

OBJECTIVES

The main aim of this systematic review was to evaluate the prevalence and type of associated anomalies in fetuses with heterotaxy diagnosed prenatally on ultrasound; the perinatal outcome of these fetuses was also studied.

METHODS

An electronic search of MEDLINE, EMBASE and CINAHL databases was performed. Only studies reporting the prenatal diagnosis of isomerism were included. Outcomes observed included associated cardiac and extracardiac anomalies, fetal arrhythmia, abnormal karyotype, type of surgical repair and perinatal mortality. The analysis was stratified according to the type of heterotaxy syndrome (left (LAI) or right (RAI) atrial isomerism). Meta-analyses of proportions were used to combine data. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale for cohort studies.

RESULTS

Sixteen studies (647 fetuses) were included in the analysis. Atrioventricular septal defect was the most common associated major cardiac anomaly found both in fetuses with LAI (pooled proportion (PP), 59.3% (95% CI, 44.0-73.7%)), with obstructive lesions of the right outflow tract occurring in 35.5% of these cases, and in fetuses with RAI (PP, 72.9% (95% CI, 60.4-83.7%)). Fetal arrhythmias occurred in 36.7% (95% CI, 26.9-47.2%) of cases with LAI and were mainly represented by complete atrioventricular block, while this finding was uncommon in cases with RAI (PP, 1.3% (95% CI, 0.2-3.2%)). Abnormal stomach and liver position were found, respectively, in 59.4% (95% CI, 38.1-79.0%) and 32.5% (95% CI, 11.9-57.6%) of cases with LAI, and in 54.5% (95% CI, 38.5-70.1%) and 45.9% (95% CI, 11.3-83.0%) of cases with RAI, while intestinal malrotation was detected in 14.2% (95% CI, 2.5-33.1%) of LAI and 27.1% (95% CI, 7.9-52.0%) of RAI cases. Hydrops developed in 11.8% (95% CI, 2.9-25.6%) of fetuses diagnosed prenatally with LAI. Biventricular repair was accomplished in 78.2% (95% CI, 64.3-89.4%) of cases with LAI, while univentricular repair or palliation was needed in 17.0% (95% CI, 9.7-25.9%); death during or after surgery occurred in 26.8% (95% CI, 4.6-58.7%) of LAI cases. Most children with RAI had univentricular repair and 27.8% (95% CI, 15.5-42.1%) died during or after surgery.

CONCLUSIONS

Fetal heterotaxy is associated with a high prevalence of cardiac and extracardiac anomalies. Approximately one quarter of fetuses with heterotaxy died during or after surgery. Abnormal heart rhythm, especially heart block, is common in fetuses with LAI, while this finding is uncommon in RAI. Biventricular repair was common in LAI while univentricular repair was required in the majority of children affected by RAI. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal Findings in Left Atrial Isomerism and an Overview of Heterotaxy Syndrome

Heterotaxy syndrome is a rare, complex disorder involving structural cardiac defects in combination with symmetrical development of abdominal viscera that are normally asymmetrical organs. The vast assortment of cardiac manifestations with accompanying abdominal visceral variations determines the prognosis of heterotaxy syndrome. This case study provides an example of the management of this disease, which is unique to the patient. This is a case report of heterotaxy syndrome diagnosed in utero at 29 weeks and 4 days.

Cilia: Organelles at the Heart of Heart Disease

Genetic disorders, such as heterotaxy, first provided a link between cilia and developmental heart defects. Now, a genetic screen in mice shows that ciliary dysfunction may indeed be the major contributing factor in the etiology of congenital heart disease.

Global genetic analysis in mice unveils central role for cilia in congenital heart disease

Congenital heart disease (CHD) is the most prevalent birth defect, affecting nearly 1% of live births; the incidence of CHD is up to tenfold higher in human fetuses. A genetic contribution is strongly suggested by the association of CHD with chromosome abnormalities and high recurrence risk. Here we report findings from a recessive forward genetic screen in fetal mice, showing that cilia and cilia-transduced cell signalling have important roles in the pathogenesis of CHD. The cilium is an evolutionarily conserved organelle projecting from the cell surface with essential roles in diverse cellular processes. Using echocardiography, we ultrasound scanned 87,355 chemically mutagenized C57BL/6J fetal mice and recovered 218 CHD mouse models. Whole-exome sequencing identified 91 recessive CHD mutations in 61 genes. This included 34 cilia-related genes, 16 genes involved in cilia-transduced cell signalling, and 10 genes regulating vesicular trafficking, a pathway important for ciliogenesis and cell signalling. Surprisingly, many CHD genes encoded interacting proteins, suggesting that an interactome protein network may provide a larger genomic context for CHD pathogenesis. These findings provide novel insights into the potential Mendelian genetic contribution to CHD in the fetal population, a segment of the human population not well studied. We note that the pathways identified show overlap with CHD candidate genes recovered in CHD patients, suggesting that they may have relevance to the more complex genetics of CHD overall. These CHD mouse models and >8,000 incidental mutations have been sperm archived, creating a rich public resource for human disease modelling.

Defects in laterality with emphasis on heterotaxy syndromes with asplenia and polysplenia: an autopsy case series at a single institution

Heterotaxy is a rare disease with high morbidity and mortality. Controversy exists over how to classify these syndromes with most cases stratified into asplenia/polysplenia syndromes or right/left isomerism. In an effort to review comprehensively specific pheonotypes associated with heterotaxy syndromes, we reviewed published cases series, adopted a classification scheme based on spleen status, and evaluated autopsy cases retrospectively with abnormal laterality at our institution. We categorized 116 cases as situs inversus totalis, polysplenia, asplenia, and single right-sided spleen. Cardiovascular abnormalities occurred in 87.1% of polysplenia, 90.5% of asplenia, and all cases of single right-sided spleen. For polysplenia, 48.9% had bilateral bilobed lungs, 87% had right-sided stomach, 58.1% had midline symmetric liver, and 60.4% had malrotated intestines. For asplenia, 51.9% had bilateral trilobed lungs, 86.7% had right-sided stomach, 45.8% had symmetric liver, and 65.5% had malrotated intestines. Atrioventricular septal defects occurred in 91.2% of asplenia compared to 56.8% of polysplenia cases. Eight percent had pulmonary/aortic stenosis or atresia. Double outlet right ventricle was more common in polysplenia (32.6%) compared to asplenia (21.4%). Total anomalous systemic venous return was described in 55.6% of polysplenia and total anomalous pulmonary venous connections in 81% of asplenia cases. Greater than half of the cases had no heterotaxy diagnosis. Although, we found similar heterotaxy-associated characteristics, the frequencies differed from previous studies. We found great variation in how heterotaxy-associated defects were described, diagnosed, and reported. Although there are known associated characteristics with the polysplenia/asplenia syndromes, correct identification requires a standardized approach for diagnosis and reporting.

Prenatal diagnosis of atrial isomerism in the Korean population

OBJECTIVE

To report our experiences in the prenatal diagnosis of atrial isomerism and postnatal outcomes.

METHODS

A total of 80 fetuses prenatally diagnosed with atrial isomerism were retrospectively analyzed between 1999 and 2011 at a single institution.

RESULTS

Of 43 fetuses with prenatally diagnosed right atrial isomerism (RAI), 40 cases were analyzed. The diagnostic accuracy was 93%. The main intracardiac anomalies in RAI were atrioventricular septal defect (AVSD), abnormal pulmonary venous connection, bilateral superior vena cava (BSVC), and pulmonary atresia. Among 28 live births, three infants were lost to follow up, and the overall survival rate was 60%. Of 37 fetuses with prenatally diagnosed left atrial isomerism (LAI), 35 were evaluated. The diagnostic accuracy was 97%. The main intracardiac anomalies in LAI were ventricular septal defect, BSVC, AVSD, double outlet right ventricle, and bradyarrhythmia. Among seven patients with bradyarrhythmia, only one showed a complete atrioventricular block. All fetuses had an interrupted inferior vena cava with azygous continuation. The overall survival rate was 90%.

CONCLUSION

Our study confirms the previous findings of fetal atrial isomerism. We also demonstrates a much lower prevalence of AVSD and complete heart block in LAI and a better survival rate in RAI. Although the postnatal outcomes for RAI were worse than those for LAI, successful postnatal surgery with active management improved the survival rate.

Role of four-dimensional ultrasound (spatiotemporal image correlation and sonography-based automated volume count) in prenatal assessment of atrial morphology in cardiosplenic syndromes

OBJECTIVE

To assess the diagnostic role of four-dimensional ultrasound using spatiotemporal image correlation and Sonography-based Automated Volume Count (STIC-SonoAVC) in the identification of the morphology of the atrial appendages in cases with cardiosplenic syndrome.

METHODS

This was a retrospective investigation of 22 fetuses with cardiosplenic syndromes seen at our institution over a 5-year period from January 2004. As control groups, 10 normal fetuses, five cases with a non-isomeric atrioventricular septal defect and five cases with other congenital heart diseases were also analyzed. For all fetuses, one or more cardiac volume datasets were available for offline analysis. Two-dimensional and four-dimensional echocardiography was carried out in all cases at the time of diagnosis using high quality three-dimensional equipment. Dedicated software was used to assess chamber morphology using the SonoAVC technique, which allows the creation of casts of hollow structures. Two different operators used the software. The first performed all steps up to positioning of the region of interest box. The second operator, who was blinded to clinical information, then rendered the cardiac chambers using the SonoAVC technique. This operator then used the rendered image to subjectively assess atrial morphology.

RESULTS

Suitable rendered images of the cardiac chambers could be produced in 40/42 fetuses. In two cases of left atrial isomerism, advanced (34 weeks) and early (13 weeks) gestational age made it impossible to obtain adequate rendered images. In the remaining 40 cases (13 cases of left atrial isomerism, seven cases of right atrial isomerism, five cases of non-isomeric atrioventricular septal defect, five cases of other congenital heart diseases and 10 normal fetuses), atrial morphology was correctly identified by evaluation of the rendered images.

CONCLUSION

Four-dimensional ultrasound with SonoAVC rendering allows correct identification of the morphology of atrial appendages in all cases of cardiosplenic syndromes in which an adequate cardiac volume dataset can be obtained for analysis.

Right Atrial Isomerism – Preponderance in Asian Fetuses. Using the Stomach-distance ratio as a Possible Diagnostic Tool for Prediction of Right Atrial Isomerism

Introduction: To present the characteristics and spectrum of associated anomalies in right- and left-sided isomerism in our local population and to assess the possibility of using stomach-distance ratio (SDR) of less than 0.34 as a diagnostic tool to predict right atrial isomerism. Materials and Methods: This was a retrospective study of fetuses in our department over a period of 8 years with postnatally confirmed prenatal diagnosis of atrial isomerism. Results: In 22 cases, atrial isomerism was confirmed by post-mortem or postnatal echocardiography. Eighteen (81.8%) fetuses had right isomerism. Their main abnormal ultrasound findings were pulmonary stenosis or atresia (n = 9), atrioventricular septal defect (n = 10), right-sided stomach (n = 9), transposition of great arteries (n = 6), dextrocardia (n = 8), single ventricle (n = 4), juxtaposition of inferior vena cava and descending aorta (n = 5), ventricular septal defect (n = 2), interrupted inferior vena cava with azygous drainage (n = 2) and double outlet right ventricle (n = 3). Four (18.2%) fetuses had left isomerism. Their abnormal ultrasound findings were dextrocardia (n = 3), right-sided stomach (n = 3), atrioventricular septal defect (n = 2), double outlet ventricle (n = 2), ventricular septal defect (n = 1), pulmonary stenosis (n = 2) and interrupted inferior vena cava with azygous drainage (n = 1). 66.7% (12/18) of cases with right isomerism had SDR of less than 0.34 compared to 0% (0/4) of the cases with left isomerism (P = 0.02). Conclusion: Our study suggests an Asian predilection towards right isomerism compared to Western populations. We postulate that there may be racial differences in the expression of these 2 forms of isomerism. The ultrasound findings of complex heart disease and abnormal arrangement of great vessels in abdominal cavity, though important, are varied and non-specific evidence for either form of fetal atrial isomerism. There is a possibility of using the SDR <0.34 (representing stomach proximity to the fetal spine) as a possible diagnostic tool to predict right-sided atrial isomerism. Key words: Azygous vein, Cardiac defects, Dextrocardia, Heterotaxy syndrome, Stomach localisation, Stomach near spine, Visceral heterotaxy

The area behind the heart in the four-chamber view and the quest for congenital heart defects

OBJECTIVE

To evaluate the spectrum of fetal cardiac defects associated with abnormal sonographic findings in the area behind the heart (ABTH) in the four-chamber view.

METHODS

This study included a retrospective review of 393 fetuses with congenital heart defects (CHD) detected in 2003-2005 at our tertiary referral center and a prospective evaluation of 4666 fetal echocardiograms, including 220 cases of CHD, performed between January 2006 and February 2007. The retrospective and prospective groups did not differ significantly with respect to cardiac anomalies or abnormal findings in the ABTH, allowing us to combine the 613 fetuses with CHD investigated over a 50-month period.

RESULTS

In the study period, 69 fetuses had abnormalities of the ABTH (75% with major CHD). In 28 fetuses, two equally sized vessels ran behind the heart. Of these, 26 had an interrupted inferior vena cava with azygos continuation and two had total anomalous infracardiac pulmonary venous connection. In 41 fetuses, only one vessel was visualized, but the descending thoracic aorta was positioned contralateral to the cardiac apex. Of these, 29 had levocardia with right descending aorta. All of them had a right aortic arch. The remaining 12 had dextrocardia with left descending aorta.

CONCLUSIONS

The ABTH in the four-chamber view is easy to evaluate and offers important diagnostic markers for fetal CHD. Thus, it might enhance the screening performance of the four-chamber view. Attention must be paid to the number of vessels behind the heart and their laterality.

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.

Heterotaxy syndrome with functional single ventricle: does prenatal diagnosis improve survival?

BACKGROUND

Despite improved outcome for many single ventricle lesions, staged reconstruction for heterotaxy syndrome with a functional single ventricle continues to have a high mortality. Prenatal identification of heterotaxy syndrome may improve long-term survival.

METHODS

Our database was reviewed from January 1996 to December 2004 for patients with heterotaxy syndrome. Assessment was made for prenatal diagnosis and echocardiographic characteristics of heterotaxy syndrome. We sought to assess the accuracy of fetal echocardiography in the diagnosis of heterotaxy syndrome and determine whether prenatal diagnosis and other risk factors have an impact on survival in patients with heterotaxy syndrome.

RESULTS

Of 81 patients that met criteria, 43 (53%) had prenatal diagnosis. Prenatal diagnosis had high specificity and positive predictive value for all findings but had low sensitivity for anomalous pulmonary veins. Among the 70 patients born alive, survival was 60% with median follow-up of 51.4 months (range, 6.5 to 109.7 months). Prenatal diagnosis did not improve survival (p = 0.09). None of the 11 patients with complete heart block (CHB) survived past 3 months of age. Two patients underwent heart transplantation as their first intervention and have survived. CHB and anomalous pulmonary venous connection were associated with shorter duration of survival.

CONCLUSIONS

Prenatal diagnosis of heterotaxy syndrome does not improve survival in patients who undergo single ventricle reconstruction. The most potent risk factors for poor outcome (CHB, anomalous pulmonary veins) are likely not impacted by identification in utero. In light of the poor outcome, cardiac transplantation as an initial therapy may be a viable option for some patients.

Spectrum of cardiovascular disease, accuracy of diagnosis, and outcome in fetal heterotaxy syndrome

Because there is a paucity of information regarding the diagnosis and outcomes of fetal heterotaxy syndrome (HS), this study sought to determine the spectrum of cardiac pathology, accuracy of diagnosis, and outcome of fetal HS. All cases of fetal HS encountered in the investigators' institution over a 10-year period through 2002 were identified. Prenatal and postnatal echocardiograms and medical records were reviewed. Seventy-one fetuses were diagnosed with HS, including 48 with left atrial isomerism (LAI) and 23 with right atrial isomerism (RAI). For LAI and RAI, most intracardiac lesions, the pulmonary venous connections, and superior vena caval anatomy were correctly diagnosed in utero (93%, 86%, and 77% accuracy, respectively), whereas hepatic venous connections and inferior vena caval-atrial connections in RAI were difficult to define (65% and 56% accuracy, respectively). Of 32 continued and followed pregnancies with LAI, 22 are currently alive at 48 +/- 30 months. Heart block and associated major extracardiac pathology were significantly more common in nonsurvivors with fetal LAI (p = 0.007 and 0.024, respectively). Outcomes were even worse for prenatally diagnosed RAI: of 14 continued pregnancies, only 3 are currently alive. In conclusion, fetal HS is associated with a broad spectrum of cardiac pathology, which can be diagnosed accurately in utero. Fetal LAI is associated with a mortality of 31%, with heart block and extracardiac pathology as primary risk factors for perinatal mortality. The outcome of prenatally diagnosed RAI is poor.

Clinical Features, Management, and Outcome of Children With Fetal and Postnatal Diagnoses of Isomerism Syndromes

Background— Isomerism is associated with a complex spectrum of anomalies. There is paucity of data on prenatally detected cases.

Methods and Results— Between January 1990 and February 2004, 83 of 166 cases (50%) had a prenatal diagnosis of left isomerism (LAI; 52 of 97) or right isomerism (RAI; 31 of 69) at our institution. The spectrum of anomalies, management, and outcomes was compared for fetal and postnatal diagnoses of LAI and RAI. RAI more often than LAI was associated with AV septal defect (90% versus 56%; P <0.0001), pulmonary outflow obstruction (91% versus 37%; P <0.0001), total anomalous pulmonary venous drainage (73% versus 13%; P <0.0001), and abnormal VA connections (68% versus 33%; P <0.0001), whereas inferior vena cava interruption (3% versus 93%; P <0.0001), complete AV block (0% versus 13%; P =0.004), aortic obstruction (6% versus 33%; P <0.0001), and extracardiac defects (5% versus 25%; P =0.006) were less common. The spectrum of lesions was comparable for fetal and postnatal cases, except for AV block (fetal, 25%; postnatal, 0%; P =0.0002) and AV septal defect (fetal, 67%; postnatal, 42%; P =0.023) in LAI. Fetal demise was due mainly to pregnancy termination (LAI, 42%; RAI, 45%). Survival of actively managed children with LAI was significantly better than for those with RAI ( P <0.0001) but did not differ with regard to fetal versus postnatal diagnosis. Most LAI cases required no intervention or underwent successful biventricular cardiac surgery (65%), unlike RAI cases (13%; P <0.0001).

Conclusions— Prenatal diagnosis did not affect overall survival despite facilitated care. The prognosis of RAI was worse compared with LAI because of more complex associated cardiac defects and the inability to perform successful surgical procedures.

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.

Totally anomalous pulmonary venous connection and complex congenital heart disease: prenatal echocardiographic diagnosis and prognosis

OBJECTIVE

The purpose of this study was to determine the accuracy of prenatal cardiac diagnosis, prognosis, and outcome of totally anomalous pulmonary venous connection (TAPVC) and to determine echocardiographic clues in the prenatal diagnosis of isolated TAPVC or TAPVC in association with other complex congenital heart disease (CHD).

METHODS

We reviewed our 13-year experience of prenatal diagnosis of TAPVC. Thirteen fetuses were identified with the diagnoses of TAPVC. We systematically analyzed the individual pulmonary veins by color and pulsed Doppler imaging, the presence of a pulmonary venous confluence, the pulsed and color Doppler evaluation of the vertical vein, and sites of connections. Prenatal diagnosis was confirmed by postnatal echocardiography, cardiac catheterization, surgery, or autopsy.

RESULTS

The mean gestational age at diagnosis of TAPVC was 26.3 weeks (range, 20-33 weeks). There were 8 fetuses with TAPVC and right isomerism, 3 fetuses with other associated CHD, and 2 with isolated TAPVC. There were 7 fetuses with supracardiac TAPVC, 4 with infracardiac TAPVC, and 2 with mixed TAPVC. Pulmonary vein color and pulsed Doppler data were available in 10 of 13 fetuses. The pulmonary venous confluence was visualized in all fetuses except 1. The vertical vein was visualized in all fetuses. Five fetuses had suspected signs of obstruction. The diagnosis was confirmed postnatally or at autopsy in 12 cases. Eight patients underwent surgery; 6 died, and 2 were alive. Two patients had compassionate care and died; 3 pregnancies were terminated.

CONCLUSIONS

It is possible to diagnose accurately complex CHD, including the pulmonary venous connections. When diagnosed prenatally, TAPVC carries a poor prognosis.

Heterotaxy syndrome -- asplenia and polysplenia as indicators of visceral malposition and complex congenital heart disease

Heterotaxy results from failure of the developing embryo to establish normal left-right asymmetry. Typical manifestations include abnormal symmetry and malposition of the thoraco-abdominal organs and vessels, complex congenital heart disease and extracardiac defects involving midline-associated structures. The spleen is almost always affected, and there is syndromic clustering of the malformations corresponding to the type of splenic abnormality present. This review outlines the embryologic and genetic background of the heterotaxy syndrome as well as the characteristic anatomic features, clinical manifestations, and diagnostic clues of its two main presentations with asplenia or polysplenia.

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

OBJECTIVES

To assess the spectrum of anomalies associated with fetal heart block and to identify possible prognostic markers.

METHODS

Retrospective review of all cases of second- or third-degree heart block identified in two tertiary referral centers in Germany (Bonn and Lübeck) and one in the USA (Baltimore).

RESULTS

Sixty fetuses with heart block were identified in the study period. Thirty-two had complex cardiac malformations, 31 of them associated with left isomerism. The outcomes of these fetuses were 22 terminations of pregnancy (TOP), three intrauterine fetal deaths (IUFD), three neonatal deaths (NND), two childhood deaths (CD) and there were two survivors. In 20 cases without complex cardiac malformations maternal antinuclear-antibodies were detected. Their outcomes were 2 TOP, 1 IUFD, 1 NND and 16 survived. The remaining eight cases had neither complex cardiac malformations nor associated maternal antibodies. Their outcomes were 1 TOP, 2 IUFD, 2 NND and 3 survived. After exclusion of terminated cases, hydrops as well as the presence of cardiac defects was significantly associated with non-survival (P < 0.01). The cardiothoracic circumference ratio was significantly higher in hydropic fetuses and significantly negatively correlated with survival in immune-mediated cases (P < 0.01). Atrial and ventricular frequencies and their evolution did not accurately predict fetal or neonatal outcome. Sympathomimetic treatment in seven cases was not associated with favorable fetal outcome in cases of hydrops or cardiac malformations.

CONCLUSIONS

The most important marker predicting adverse outcome in cases of heart block is fetal hydrops, followed by the association with complex cardiac malformations. Cases without cardiac malformations have a significantly better prognosis, especially in the absence of severe cardiomegaly.

The syndrome of left isomerism: sonographic findings and outcome in prenatally diagnosed cases

OBJECTIVE

The purpose of this study was to evaluate the accuracy of the prenatal diagnosis of left isomerism and to assess possible diagnostic and prognostic markers.

METHODS

We conducted a retrospective review of all previously unpublished cases of left isomerism diagnosed in the prenatal and postnatal periods in 2 tertiary referral centers in Germany over 15 years.

RESULTS

Among 34 fetuses, 31 had a correct prenatal diagnosis of left isomerism; 31 had an interruption of the inferior vena cava with azygos continuation; 22 had different types of viscerocardiac heterotaxy; 13 had heart block; and 28 had cardiac defects, with a high prevalence of atrioventricular septal defects (n = 24), right outflow tract obstruction (n = 11), double-outlet right ventricles (n = 6), and anomalous pulmonary venous return (n = 6). Among the 34 cases, 9 underwent termination of pregnancy; 2 fetuses died in utero; 5 children died in the neonatal period; and 4 children died in infancy. Only the presence of heart block and hydrops was significantly correlated with nonsurvival (P < .05). Fourteen children survived, with a mean follow-up +/- SD of 2.9 +/- 2.6 years. Three survivors underwent single-ventricle palliation, and 1 had successful biventricular repair. Three children were awaiting cardiac repair. The remaining 7 children had minor or no associated cardiac defects and were doing well.

CONCLUSIONS

Prenatal diagnosis of left isomerism is feasible, with high accuracy. Important diagnostic pointers are viscerocardiac heterotaxy, complex cardiac malformations, heart block, and interruption of the inferior vena cava. The mortality in fetuses and neonates is high in the presence of heart block and hydrops, whereas the cardiac defects influence the long-term outcome.

Prenatal diagnosis of transposition-like double-outlet right ventricle with mitral valve atresia in heterotaxy syndrome

We present a case of heterotaxy syndrome with right isomerism detected in a twin fetus, with the sonographic findings that established this diagnosis. At 24 weeks' menstrual age, ultrasound detected anomalies in the heart suggestive of heterotaxy syndrome. Intrauterine fetal echocardiography demonstrated that the heart of the affected twin was located on the left side with a normal cardiac axis. The right ventricle was much larger than the left ventricle. The appearance of the mitral valve was dysplastic with restricted motion. The ascending aorta exited from the right ventricle, anterior to, right to, and parallel to the smaller pulmonary trunk, which also arose from the right ventricle. Double-outlet right ventricle (DORV) was clearly demonstrated. Cesarean section was performed at 38 weeks' menstrual age. Both twins were healthy and survived. Postnatal echocardiography and MRI confirmed the prenatal findings. At the age of 4 months, the affected infant had no evidence of cardiac decompensation. This report shows that conventional ultrasound can be used to detect heterotaxy syndrome and that intrauterine fetal echocardiography can delineate the cardiac complex in heterotaxy syndrome. Postnatal surgery with complex Fontan procedures was planned for the affected twin.

Prenatal diagnosis of cardiosplenic syndromes: a 10-year experience

OBJECTIVE

To assess the accuracy of fetal echocardiography in the prenatal diagnosis of cardiosplenic syndromes and the spectrum of associated anomalies.

METHODS

This was a retrospective survey of fetuses in our databases over a period of 10 years with postnatally confirmed prenatal diagnosis of cardiosplenic syndromes.

RESULTS

In 32 of 35 fetuses the prenatal diagnosis of cardiosplenic syndromes was confirmed postpartum. Twenty-two fetuses had left isomerism. Their main prenatal ultrasound features were interrupted inferior vena cava (n = 21), complete atrioventricular septal defect (n = 15), viscerocardiac heterotaxy (n = 15), persistent bradyarrhythmia (n = 12) and fetal hydrops or nuchal edema (n = 12). Twelve pregnancies were terminated, two fetuses were stillborn and eight infants survived. Ten fetuses had right isomerism. Their main sonographic features were juxtaposition of the descending aorta and inferior vena cava (n = 7), complete atrioventricular septal defect (n = 7), left persistent superior vena cava (n = 6) and viscerocardiac heterotaxy (n = 6). In this group there was one stillbirth, five infant deaths and four survivors. The overall survival rate and spectrum of other cardiac malformations were similar between the two groups. Prenatal diagnosis of other visceral features of cardiosplenic syndromes was inconsistent.

CONCLUSION

Cardiosplenic syndromes can be diagnosed with high accuracy by prenatal sonography. A diagnosis of left isomerism should be strongly suggested in the presence of a combination of at least two of the following: (1) complete atrioventricular septal defect or other structural heart disease; (2) interruption of inferior vena cava with azygos continuation; (3) early fetal heart block; (4) viscerocardiac heterotaxy. Right isomerism should be suspected in the presence of a combination of at least two of the following: (1) structural heart disease, namely complete atrioventricular septal defect; (2) juxtaposition of inferior vena cava and descending aorta; (3) viscerocardiac heterotaxy.

The human fetal venous system: normal embryologic, anatomic, and physiologic characteristics and developmental abnormalities

OBJECTIVE

The introduction of high-resolution ultrasonography combined with color-coded Doppler imaging offered a breakthrough in the evaluation of the human fetal venous system, considerably enhancing our understanding of fetal venous circulation in normal physiologic conditions, as well as providing us the ability to study circulatory changes in abnormal circumstances. The purpose of this study was to describe the normal anatomic development and complex of anomalies of the human fetal venous system and to review recently published series of these anomalies.

METHODS

Normal embryologic and anatomic development is described. An English language literature search of recent MEDLINE listings was performed to glean data from recently published series reporting prenatal diagnosis of the various anomalies and their associated malformations.

RESULTS

Anomalies of the human fetal venous system occur sporadically, often associated with cardiac or other malformations. The pathophysiologic mechanisms leading to abnormal in utero development of the human venous system remain largely undetermined. On the basis of the type of vein involved, embryologic precursor, and etiologic correlation (primary or secondary), classification into 4 major groups is described.

CONCLUSIONS

Prenatal evaluation of fetuses found to have anomalies of the venous system should include a careful search for cardiac anomalies, including pulmonary venous drainage, and a detailed anatomic survey of the umbilical, portal, hepatic, and ductal systems to determine aberrant communication and, if possible, to discover clues to systemic diseases or thromboembolic phenomena.

In utero diagnosis of obstructed supracardiac total anomalous pulmonary venous connection in a patient with right atrial isomerism and asplenia

We describe a rare case of right atrial isomerism, levocardia, right-side stomach, obstructed supracardiac total anomalous pulmonary venous connection, double outlet right ventricle with complete atrioventricular septal defect and absent spleen. From the pulmonary venous confluence behind the atrium an ascending as well as a descending vertical vein communicated with the systemic venous system in the supracardiac as well as the infracardiac position. The pulsed and color Doppler examination of the individual pulmonary veins as well as of the vertical vein helped in making the diagnosis of obstructed total anomalous pulmonary venous connection. The diagnosis was made by fetal echocardiographic examination at 22 weeks of gestation and confirmed on postnatal echocardiography, cardiac catheterization, and at surgery.

Prenatal diagnosis and management of fetal cardiovascular malformations

Screening for fetal cardiovascular malformations is widely performed. Its accuracy is not yet satisfactory, but better training of ultrasonographers and extension from the four-chamber view to the study of the outflow tract are probably clues to an improvement. The main impact of prenatal diagnosis is still the termination of pregnancy for severe malformations and for those associated with chromosomal or extracardiac anomalies. There is now evidence that prenatal diagnosis improves perinatal morbidity or mortality for some malformations. New information about the molecular genetic basis of congenital heart disease will help in management and counselling.