Prenatal diagnosis of cardiosplenic syndromes: a 10-year experience

Congenital lobar emphysema associated with polysplenia syndrome

Polysplenia, or left isomerism, is a rare heterotaxy syndrome characterized by bilateral bi-lobed lungs, bilateral pulmonary atria, a symmetrical midline liver, and multiple aberrant splenic nodules. We report a case of polysplenia associated with congenital lobar emphysema apart from other typical anomalies. Such an association has not been previously reported. The patient was a young male with progressive exertional breathlessness referred for high resolution CT of the lungs. CT, MRI and echocardiography revealed (in addition to congenital lobar emphysema of right lung) a hemiazygos continuation of the inferior vena cava, a persistent left superior vena cava, multiple splenunculi in the right hypochondrium, midline liver, bilateral bilobed lungs, a large pulmonary artery (suggestive of severe pulmonary artery hypertension) and a large VSD--a typical constellation of findings described in polysplenia syndrome.

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

Atrioventricular septal defect recently diagnosed by fetal echocardiography: echocardiographic features, associated anomalies, and outcomes

OBJECTIVES

We report our recent experience with atrioventricular septal defect (AVSD) diagnosed in utero.

METHODS

We reviewed fetal echocardiograms diagnosed with AVSD between November 2002 and November 2004, comparing fetuses with and without aneuploidy. We compared results with previous studies.

RESULTS

Twenty (1.8%) fetuses had AVSD. Mean maternal age was 33 years (range 19-43). Mean gestational age was 26 weeks (range 18-38). Indications for fetal echocardiography were: abnormal obstetrical ultrasound (75%), chromosomal anomaly (15%), undetermined (10%). AVSD was an isolated cardiac defect in 5 (25%), associated with double-outlet right ventricle (9) or tetralogy of Fallot (3) in 12 (60%). Four had aortic arch anomalies. Atrioventricular valve regurgitation was mild in 7 (35%) and moderate in 4 (20%). Heart block existed in 2 (10%). Five (25%) with trisomy had Rastelli type A AVSD as a single lesion (odds ratio 24, P < .01). Extracardiac anomalies existed in 6, with and without aneuploidy. Pregnancy was terminated in 4 (20%), neonatal death in 4 (20%), and reparative surgery in 6 (30%), not ascertained in 6.

CONCLUSION

Atrioventricular septal defect is usually an isolated cardiac lesion in fetuses with aneuploidy. In the absence of aneuploidy, fetal AVSD is often associated with conotruncal and aortic arch abnormalities, which are important in determining outcomes. Pregnancy termination and neonatal death continue to be prevalent.

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.

Progressive fetal atrioventricular block in heterotaxy syndrome

We report a fetus with left isomerism, in whom the atrioventricular block progressed from low grade second degree to complete block and fetal hydrops. While it is known that there is a high incidence of heart block in the fetus with left isomerism, as far as we are aware, ours is the first report of Wenckebach type block documented in the fetus by Doppler echocardiography, and demonstration of the progression of heart block during fetus life in the setting of left isomerism.

Clinical significance of persistent left superior vena cava diagnosed in fetal life

OBJECTIVES

To determine the prevalence and clinical significance of persistent left superior vena cava (PLSVC) in fetuses with and without cardiac and extracardiac anomalies.

METHODS

Charts and recorded images were reviewed from high-risk patients who underwent fetal echocardiography between January 2000 and December 2005. This retrospective study included 54 fetuses with confirmed PLSVC who were diagnosed based on the presence of an additional vessel identified to the left of the pulmonary artery in the three-vessel view of the heart. Associated congenital heart defects (CHDs), extracardiac abnormalities, including first trimester nuchal translucency (NT) thickness, and fetal/postnatal outcome were analyzed.

RESULTS

Of 5,737 referrals, 5,233 had a normal heart, and PLSVC was observed in 10 of these fetuses (0.2%; Group 1). CHDs were present in 504 and PLSVC was observed in 44 of these cases (9%). In the latter group, 18/44 (41%) fetuses had heterotaxy syndrome (Group 2) where the most common structural heart defects were atrioventricular septal defect and double-outlet right ventricle. Fetuses without heterotaxy syndrome (Group 3) accounted for 26/44 (59%) cases of CHDs associated with PLSVC. In this group of fetuses the most common CHDs were left outflow tract obstructive defects and conotruncal anomalies. Increased NT was observed in 29%, without differences among the three groups. The survival rates among fetuses in Groups 1, 2 and 3 were 100%, 44% and 50%, respectively. After excluding patients who underwent pregnancy termination, there were no significant differences in the survival rates among the groups, probably due to the small size of the samples. CONCLUSIONS PLSVC is associated with CHDs. The identification of PLSVC should prompt a thorough examination of the fetus to identify additional cardiac and extracardiac anomalies. The prognosis of affected fetuses largely depends on whether or not the PLSVC is associated with a CHD.

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.

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.

Biliary atresia

Biliary atresia (BA) is a rare disease characterised by a biliary obstruction of unknown origin that presents in the neonatal period. It is the most frequent surgical cause of cholestatic jaundice in this age group. BA occurs in approximately 1/18,000 live births in Western Europe. In the world, the reported incidence varies from 5/100,000 to 32/100,000 live births, and is highest in Asia and the Pacific region. Females are affected slightly more often than males. The common histopathological picture is one of inflammatory damage to the intra- and extrahepatic bile ducts with sclerosis and narrowing or even obliteration of the biliary tree. Untreated, this condition leads to cirrhosis and death within the first years of life. BA is not known to be a hereditary condition. No primary medical treatment is relevant for the management of BA. Once BA suspected, surgical intervention (Kasai portoenterostomy) should be performed as soon as possible as operations performed early in life is more likely to be successful. Liver transplantation may be needed later if the Kasai operation fails to restore the biliary flow or if cirrhotic complications occur. At present, approximately 90% of BA patients survive and the majority have normal quality of life.

Accuracy of fetal echocardiography: a cardiac segment-specific analysis

OBJECTIVE

In patients with congenital heart disease, comprehensive, segment-specific analysis of cardiac anatomy has become 'the standard of care', largely as a result of improvements in cardiac imaging technology. Our aim was to apply segment-specific standards to assess the accuracy of fetal echocardiography.

METHODS

This was a retrospective review of all fetal echocardiograms (n = 915) performed at our center between August 1998 and June 2003. Of these, 100 studies had congenital heart disease findings and corresponding postnatal studies on the same patients for comparison. An expert independent pediatric echocardiologist, using the standards of accuracy expected of postnatal echocardiography, assessed the studies for the following cardiac segments: abdominal situs, systemic venous return (VR), pulmonary VR, atria, atrioventricular valves, ventricular septum, ventricular hypoplasia, ventricular morphology, semilunar valves, great arterial relation and aortic arch. Sensitivity, specificity, and positive and negative predictive values were calculated for each segment.

RESULTS

Specificity and negative predictive value were high for all cardiac segments (range, 82-100%). Sensitivity and positive predictive value were similarly high (range, 83-100%) for most cardiac segments, but were only 50-88% for systemic VR, pulmonary VR and aortic arch segments.

CONCLUSIONS

Fetal echocardiography has excellent diagnostic accuracy in describing intracardiac anatomy. However, despite both technological advances and improved physician awareness, assessment of systemic VR, pulmonary VR, and aortic arch anatomy remain challenging.

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.

Prenatal diagnosis of persistent left superior vena cava and its associated congenital anomalies

OBJECTIVE

To evaluate the associated conditions and the outcome of persistent left superior vena cava (PLSVC) detected in fetal life.

METHODS

This was a retrospective review of all cases of PLSVC detected prenatally between 1998 and 2004 in two tertiary referral centers in Germany. Patient charts, ultrasound video recordings and still frames of all cases were reviewed for associated conditions and outcome.

RESULTS

Eighty-two cases of PLSVC were detected in the study period. Thirty-seven cases (45%) were associated with heterotaxy syndromes, 19 (23%) with isolated cardiac malformations, seven (9%) with aneuploidy, six (7%) with complex malformation syndromes and six (7%) with isolated extracardiac malformations. Seven cases (9%) had no associated condition. Eighty-three percent of the fetuses in this series had associated cardiac malformations; the most frequent cardiac malformations in those with heterotaxy syndromes were complete atrioventricular septal defect (75%) and right outflow tract obstruction (58%). After exclusion of cases with heterotaxy, most congenital heart defects were ventricular septal defects (41%) and coarctation (34%). The outcome of PLSVC was determined solely by the associated conditions. After exclusion of terminated cases, heterotaxy syndromes as well as complete atrioventricular septal defects were associated significantly with perinatal and infant death. In contrast, all cases with isolated PLSVC or associated correctable extracardiac malformations survived and were doing well at the time of writing.

CONCLUSIONS

PLSVC detected in fetal life has to be followed by a meticulous inspection of the fetal anatomy as it is frequently associated with heterotaxy syndromes, other cardiac/non-cardiac malformations and aneuploidy that determine the outcome. Isolated PLSVC is a benign vascular anomaly and may not affect the outcome.

Early fetal echocardiography: heart biometry and visualization of cardiac structures between 10 and 15 weeks' gestation

OBJECTIVE

The purpose of this prospective cross-sectional study was to compile normative data about biometry of the fetal heart and great vessels between 10 and 15 weeks in 123 normal singleton pregnancies. Additionally, we investigated the different methods and the optimal examination time of early fetal echocardiography.

METHODS

The interrogated parameters included total heart diameter; heart area and circumference; right and left ventricular diameter; diameter, circumference, and area of the thorax; and diameter of the aorta and pulmonary trunk. Visualization of the 4-chamber view, 3-vessel view, origin and crossover of the great arteries, aortic arch, ductus arteriosus, superior and inferior venae cavae, and pulmonary veins was analyzed, and the success rates by transvaginal sonography (TVS) and transabdominal sonography (TAS) were calculated.

RESULTS

Complete evaluation of the fetal heart was impossible at 10 weeks; the total success rate increased from 45% at 11 weeks to 90% between 12 and 14 weeks and 100% at 15 weeks. Between 10 and 13 weeks, TVS was superior to TAS. At 14 weeks, both methods were similar to each other, and at 15 weeks, TAS allowed adequate visualization of all structures. Linear regression analysis showed a significant correlation between the interrogated parameters and gestational age, crown-rump length, and biparietal diameter (P < .05). The ratio of right and left ventricular diameters and the ratio of pulmonary trunk and aortic diameters were constant.

CONCLUSIONS

Early fetal heart evaluation by TVS or TAS or both is reasonable and feasible. Our normative data could be helpful for understanding the normal development of the fetal heart and great arteries and for detection of cardiac defects in early pregnancy.

3-Dimensional Mapping and Radiofrequency Ablation of Atrial Flutter in a Patient with Interrupted Inferior Vena Cava

The presence of isolated interrupted inferior vena cava (IVC) is very rare. Though the occurrence of typical atrial flutter in this setting has recently been described, the use of 3-dimensional activation mapping to aid the management of such patients has not yet been described. We report the successful ablation of this arrhythmia in a 63-year-old woman using the superior route through the internal jugular vein with the help of a mapping system.

Genetics of human heterotaxias

The past decade has seen remarkable advances in defining the molecular mechanisms underlying formation of the embryonic left right (LR) axis. This information is slowly transforming our understanding of human birth defects that are caused by disturbed LR axis patterning. Reversals, isomerisms, or segmental discordances of thoraco-abdominal organ position, that is, classic heterotaxy, clearly indicate embryonic disruption of normal LR patterning. Other isolated birth defects, particularly cardiovascular malformations, may be caused by deficiencies in the same pathways. Here, we review the distinctive clinical features of human heterotaxias and try to summarize the known connections between them and the corresponding developmental pathways.

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.

Isomerism of the left atrial appendage associated with ventricular noncompaction

This study investigated the rare association of ventricular noncompaction with isomerism of the left atrial appendage and heart block, demonstrating a dire prognosis for this condition. Prenatal recognition is possible by ultrasound, facilitating appropriate prenatal counseling.

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.

First-trimester fetal heart block and increased nuchal translucency: an indication for early fetal echocardiography

Prevalence of congenital heart disease increases with nuchal translucency (NT) thickness. First-trimester fetal bradycardia may result from heart block associated with complex congenital heart disease. We report two cases detected in the first trimester of pregnancy, in which both fetuses showed an increased nuchal translucency and bradycardia. Fetal karyotype was normal in both fetuses. First-trimester fetal echocardiography was performed and, in both cases, complex congenital heart disease was diagnosed. We discuss the added role of fetal heart rate in first-trimester ultrasound screening, in fetuses with increased nuchal translucency and normal karyotype. We stress, as well, the importance of echocardiography performed in the first trimester as a potential tool for early diagnosis in selected cases.

Relative risk of abnormal karyotype in fetuses found to have an atrioventricular septal defect (AVSD) on fetal echocardiography

One hundred and twenty-five fetuses were identified as having an AVSD with normal venous connections, normal arterial connections and normal cardiac situs on fetal echocardiography. Fetal karyotype was known in 111 of these cases. The relative risk of fetal trisomy 21 at mid-trimester was 107 (95% CI 87-127) times the expected number of cases compared with risk from maternal age alone, and that for trisomy 21,18 or 13 was 95 (95% CI 79-109). This data may be useful in counselling pregnant women about risk of fetal karyotypic abnormality after a diagnosis of fetal AVSD.

Breaking symmetry: a clinical overview of left-right patterning

It is increasingly recognized that mutations in genes and pathways critical for left-right (L-R) patterning are involved in common isolated congenital malformations such as congenital heart disease, biliary tract anomalies, renal polycystic disease, and malrotation of the intestine, indicating that disorders of L-R development are far more common than a 1 in 10,000 incidence of heterotaxia might suggest. Understanding L-R patterning disorders requires knowledge of molecular biology, embryology, pediatrics, and internal medicine and is relevant to day-to-day clinical genetics practice. We have reviewed data from mammalian (human and mouse) L-R patterning disorders to provide a clinically oriented perspective that might afford the clinician or researcher additional insights into this diagnostically challenging area.

Fetal cardiac anomalies and genetic syndromes

Cardiac anomalies may occur in isolation or can be part of a genetic syndrome. In this article, we describe some of the genetic syndromes commonly associated with cardiac anomalies where there are other sonographic features that may aid accurate prenatal diagnosis.