Prenatally diagnosed pulmonary atresia with ventricular septal defect: echocardiography, genetics, associated anomalies and outcome

OBJECTIVE

To assess the accuracy of prenatal diagnosis, the association with genetic and extracardiac anomalies, and outcome in fetuses with isolated pulmonary atresia with ventricular septal defect (PA-VSD).

DESIGN AND SETTING

Retrospective study in a tertiary centre for fetal cardiology.

PATIENTS AND OUTCOME MEASURES

Echocardiographic video recordings of 27 consecutive fetuses with PA-VSD were reviewed for: (1) intracardiac anatomy; (2) presence of confluence and size of the branch pulmonary arteries; (3) source of pulmonary blood supply; and (4) side of the aortic arch. Postmortem and postnatal data were added. Karyotyping was performed in 25 patients and, in 23 of these, fluorescent in situ hybridisation to identify 22q11.2 deletion.

RESULTS

PA-VSD was correctly diagnosed in 19 of 21 patients (90%) with postnatal or autopsy confirmation of diagnosis. Central pulmonary arteries were correctly identified in 79% (15/19), the source of pulmonary blood supply in 62% (13/21) and major aortopulmonary collateral arteries in 44% (4/9). Aneuploidy was detected in 4 of 25 patients (16%) and 22q11.2 deletion in 6 of 23 patients (26%). Five of 27 patients (19%) had extracardiac anomalies. Eleven pregnancies were interrupted. Eleven of 16 liveborn babies survived. Neonatal survival was 15 of 16 (94%, 95% confidence interval (CI) 70 to 100), one-year survival was 9 of 12 (75%, 95% CI 43 to 95) and two-year survival was 5 of 9 (56%, 95% CI 21 to 86).

CONCLUSION

PA-VSD can be diagnosed by fetal echocardiography with a high degree of accuracy. However, it can be difficult to determine the morphology of the central pulmonary arteries and to locate the source of pulmonary blood supply. In most liveborn infants, complete surgical repair can be achieved.

Outcome after preterm delivery of infants antenatally diagnosed with congenital heart disease

OBJECTIVE

To determine outcome of delivery before 36 weeks gestation in babies diagnosed antenatally with serious congenital heart disease (CHD).

STUDY DESIGN

A retrospective database review at 2 tertiary care fetal cardiology centers. Details of neonatal course and outcome were obtained for those antenatally diagnosed with serious CHD who were live born before 36 weeks gestation.

RESULTS

Between January 1998 and December 2002, 9918 women were referred for fetal echocardiography. Serious CHD was diagnosed in 1191 fetuses (12%), of which 46 (4%) delivered prematurely. Median gestation was 33 (range 24-35) weeks, and median birth weight 1.56 (0.50-3.59) kg. Extracardiac/karyotypic anomalies occurred in 23 (50%). Twenty-six babies (57%) underwent neonatal surgery: 16 a cardiac procedure, 5 a general surgical procedure, and 5 both. Eight died during or after operation (31%). Two babies underwent interventional heart catheterization; both died. The overall mortality rate was 72%. Extracardiac/karyotypic anomalies increased the relative risk of death by a factor of 1.36. Mean hospital stay for those surviving to initial discharge was 46 (2-137) days.

CONCLUSIONS

There is a very high morbidity and mortality rate in this group, particularly for those with extracardiac/karyotypic anomalies. This should be reflected in decisions over elective preterm delivery and when counseling parents.

Fetal dextrocardia: diagnosis and outcome in two tertiary centres

OBJECTIVE

To evaluate the incidence of fetal dextrocardia, associated cardiac and extracardiac malformations, and outcome.

DESIGN

Retrospective echocardiographic study.

SETTING

Two tertiary centres for fetal cardiology.

PATIENTS

81 consecutive fetuses with a fetal dextrocardia presenting at Guy's Hospital, London, between 1983 and 2003 and at Hôpital Robert Debré, Paris, between 1988 and 2003. Fetal dextrocardia was defined as a condition in which the major axis of the heart points to the right.

RESULTS

The incidence was 0.22%. There were 38 fetuses (47%) with situs solitus (SS), 24 (30%) with situs ambiguus (SA), and 19 (23%) with situs inversus (SI). Structural cardiac malformations were found in 25 cases (66%) of SS, 23 cases (96%) of SA, and 12 cases (63%) of SI. Extracardiac malformations were identified in 12 cases (31%) of SS, in five cases (21%) of SA, and in two cases (10%) of SI. Of the 81 cases of fetal dextrocardia, there were 27 interrupted pregnancies (15 of 24 SA, 10 of 38 SS, and 2 of 19 SI), six intrauterine deaths (3 of 38 SS, 2 of 24 SA, and 1 of 19 SI), and five neonatal deaths (3 of 24 SA, 1 of 19 SI, and 1 of 38 SS). There were 43 survivors (24 of 38 SS, 15 of 19 SI, and 4 of 24 SA).

CONCLUSION

The majority of fetuses with dextrocardia referred for fetal echocardiography have associated congenital heart disease. There is a broad spectrum of cardiac malformation and the incidence varies according to the atrial situs. Fetal echocardiography enables detection of complex congenital heart disease so that parents can be appropriately counselled.

Timing of presentation and postnatal outcome of infants suspected of having coarctation of the aorta during fetal life

OBJECTIVE

To report the timing of presentation and clinical profile of a cohort of fetuses with normal main cardiac connections but fetal echocardiographic signs suggestive of coarctation of the aorta.

DESIGN

Retrospective observational study.

SETTING

Tertiary fetal and paediatric cardiology centre.

PATIENTS

Between 1 January 1998 and 31 December 2002, 174 fetuses were studied, of whom 144 infants were born alive.

MAIN OUTCOME MEASURES

Of the 144 liveborn infants, 43 had coarctation of the aorta, four had interruption of the aortic arch, and one was managed as having hypoplastic left heart syndrome. Hemianomalous pulmonary venous drainage was diagnosed in two infants. Three infants with coarctation presented late at 7-13 weeks of age, 6-12 weeks after closure of the arterial duct. Fetuses with cardiac asymmetry had a higher incidence of left superior vena cava than a control group. For fetuses with cardiac asymmetry, the incidence of left superior vena cava and ventricular septal defects was similar in infants who proved to have coarctation postnatally and in those who did not. The 30 day and one year surgical mortality of infants having repair of coarctation of the aorta was two of 41 (4.9%, 95% confidence interval (CI) 0.6 to 16.0). All cause mortality of liveborn infants with any abnormality of the aortic arch was five of 48 (10.4%, 95% CI 3.5 to 22.7) at 30 days and one year, which was heavily influenced by prematurity and extracardiac abnormalities.

CONCLUSIONS

Precise diagnosis of coarctation of the aorta during fetal life remains difficult. Coarctation of the aorta may present several weeks after closure of the arterial duct and sequential echocardiography is recommended.

The low oxygen-carrying capacity of Krebs buffer causes a doubling in ventricular wall thickness in the isolated heart

The buffer-perfused Langendorff heart is significantly vasodilated compared with the in vivo heart. In this study, we employed ultrasound to determine if this vasodilation translated into changes in left ventricular wall thickness (LVWT), and if this effect persisted when these hearts were switched to the "working" mode. To investigate the effects of perfusion pressure, vascular tone, and oxygen availability on cardiac dimensions, we perfused hearts (from male Wistar rats) in the Langendorff mode at 80, 60, and 40 cm H2O pressure, and infused further groups of hearts with either the vasoconstrictor endothelin-1 (ET-1) or the blood substitute FC-43. Buffer perfusion induced a doubling in diastolic LVWT compared with the same hearts in vivo (5.4 ± 0.2 mm vs. 2.6 ± 0.2 mm, p < 0.05) that was not reversed by switching hearts to "working" mode. Perfusion pressures of 60 and 40 cm H2O resulted in an increase in diastolic LVWT. ET-1 infusion caused a dose-dependent decrease in diastolic LVWT (6.6 ± 0.4 to 4.8 ± 0.4 mm at a concentration of 10–9 mol/L, p < 0.05), with a concurrent decrease in coronary flow. FC-43 decreased diastolic LVWT from 6.7 ± 0.5 to 3.8 ± 0.7 mm (p < 0.05), with coronary flow falling from 16.1 ± 0.4 to 8.1 ± 0.4 mL/min (p < 0.05). We conclude that the increased diastolic LVWT observed in buffer-perfused hearts is due to vasodilation induced by the low oxygen-carrying capacity of buffer compared with blood in vivo, and that the inotropic effect of ET-1 in the Langendorff heart may be the result of a reversal of this wall thickening. The implications of these findings are discussed.Key words: ultrasound, endothelin, ventricular wall thickness, vasodilation.

Review of diagnosis, treatment, and outcome of fetal atrial flutter compared with supraventricular tachycardia

OBJECTIVE

To review the diagnosis, treatment, and outcome of fetal atrial flutter compared with supraventricular tachycardia.

DESIGN

Retrospective review of published reports: 11 papers about fetal tachyarrhythmia published between 1991 and 2002 were selected for review.

MAIN OUTCOME MEASURES

All selected studies were analysed for the type of arrhythmia, degree of atrioventricular block in atrial flutter, occurrence of hydrops fetalis, gestational age at diagnosis, first and second line drug treatment, associated cardiac and extracardiac malformations, and mortality of the fetuses.

RESULTS

Atrial flutter accounted for 26.2% of all cases of fetal tachyarrhythmias, and supraventricular tachycardia for 73.2%. Hydrops fetalis was reported in 38.6% and 40.5% of fetuses with atrial flutter and supraventricular tachycardia, respectively (NS). Hydropic fetuses with atrial flutter had higher ventricular rates (median 240 beats/min, range 240-300) than non-hydropic fetuses (220 beats/min, range 200-310) (p = 0.02), whereas the atrial rates were not significantly different (median 450 beats/min, range 370-500). Digoxin treatment resulted in a higher conversion rate in non-hydropic fetuses with fetal tachyarrhythmias than in hydropic fetuses (p < 0.001). The overall mortality of atrial flutter was similar to that of supraventricular tachycardia, at 8.0% v 8.9% (p = 0.7).

CONCLUSIONS

The prevalence of hydrops fetalis did not differ in fetal atrial flutter and supraventricular tachycardia with 1:1 conduction. There was no difference between the response rate to digoxin in fetus with atrial flutter or supraventricular tachycardia. Mortality was similar in the two types of tachyarrhythmia.

Echocardiographic features and outcome of truncus arteriosus diagnosed during fetal life

There are few data on the outcome of truncus arteriosus when this diagnosis is made during fetal life. Such prognostic information is important to assist parental counseling during pregnancy. This study aimed to analyze, retrospectively, the echocardiographic features and outcome of fetuses with truncus arteriosus. A database of those presenting to a tertiary center for fetal cardiology between 1990 and 1999 was reviewed. Cases in which truncus arteriosus was identified as a firm or differential diagnosis were selected. Outcome data were derived from clinical records, and fetal echocardiograms were reviewed retrospectively. At presentation, truncus arteriosus was firmly diagnosed in 16 patients and was a differential diagnosis in 12. Fourteen of 16 (87%) of the firm diagnoses were correct. There were 17 confirmed cases of truncus arteriosus. Pregnancy was terminated in 4 patients (24%) and there were 13 live births. One child was not actively treated, 4 (31%) died preoperatively, and 8 (61%) underwent surgery. Thirty-day surgical mortality was 2 of 8 (25%). There was 1 late death after cardiac catheterization, and overall survival on an intention-to-treat basis was 5 of 12 (42%). Five of 6 patients with a prenatal truncal valve Doppler velocity above the normal aortic range were found to have postnatal truncal valve stenosis. Two fetuses with stenotic valves died preoperatively with sudden cardiovascular collapse. Counseling of parents for fetuses with truncus arteriosus should include the relatively high nonsurgical mortality as well as surgical results. Elevated prenatal truncal valve Doppler velocity predicts postnatal truncal valve stenosis. Fetuses with truncal valve stenosis may be at risk of early sudden death.

The echocardiographic diagnosis of totally anomalous pulmonary venous connection in the fetus

BACKGROUND

Infants with isolated totally anomalous pulmonary venous return often present severely decompensated, such that they are at high risk for surgical repair. On the other hand, if surgical repair can be safely accomplished, the outlook is usually good. Thus prenatal diagnosis would be expected to improve the prognosis for the affected child.

OBJECTIVE

To describe the features of isolated totally anomalous pulmonary venous drainage in the fetus.

DESIGN

Four fetuses with isolated totally anomalous pulmonary venous connection were identified and the echocardiographic images reviewed. Measurements of the atrial and ventricular chambers and both great arteries were made and compared with normal values.

SETTING

Referral centre for fetal echocardiography.

RESULTS

There were two cases of drainage to the coronary sinus, one to the right superior vena cava, and one to the inferior vena cava. Right heart dilatation relative to left heart structures was a feature of two cases early on, and became evident in some ratios late in pregnancy in the remaining two.

CONCLUSIONS

Ventricular and great arterial disproportion in the fetus can indicate a diagnosis of totally anomalous pulmonary venous connection above the diaphragm. However, in the presence of an atrial septal defect or with infradiaphragmatic drainage, right heart dilatation may not occur until late in pregnancy. The diagnosis of totally anomalous pulmonary venous drainage in fetal life can only be reliably excluded by direct examination of pulmonary venous blood flow entering the left atrium on colour or pulsed flow mapping.

Isolated echogenic foci in the fetal heart as marker of chromosomal abnormality

OBJECTIVE

To assess the effect of echogenic foci in the fetal heart on the risk for Down's syndrome.

DESIGN

Prospective evaluation of fetal echocardiograms at a fetal cardiology referral center and systematic postnatal follow-up. A relative risk was calculated from the prevalence of echogenic foci in fetuses subsequently demonstrated to have trisomy 21 divided by that in normal fetuses. For a subgroup of 548 fetuses with echogenic foci but otherwise normal detailed anomaly scans, the expected number of trisomy 21 fetuses calculated from maternal age risks was compared with the observed number to derive a relative risk for isolated echogenic foci.

RESULTS

Echogenic foci occurred in 905 of 6904 fetuses scanned, but after excluding those referred specifically because of an echogenic focus and those with heart defects, the incidence was 9.5%. Overall, echogenic foci were more frequent in fetuses with trisomy 21 than those without by a factor of 2.93. For the 548 fetuses with echogenic foci but otherwise normal detailed anomaly scans, the actual number of trisomy 21 fetuses exceeded that expected on the basis of maternal age risks by a factor of 5.54. Combination with data from several previous studies suggests a consensus relative risk of about 3.0.

CONCLUSIONS

Echogenic foci are associated with increased risk of trisomy 21 even when present as an isolated finding. Their significance in an individual should be interpreted in the light of prior risk assessment based on maternal age and results of any first-trimester screening tests. We suggest that the prior risk is increased by a factor of 3.0.

Accuracy and limitations of transabdominal fetal echocardiography at 12-15 weeks of gestation in a population at high risk for congenital heart disease

OBJECTIVE

Evaluation of transabdominal fetal echocardiography at 12-15 weeks of gestation.

DESIGN

Retrospective analysis.

SETTING

Tertiary fetal cardiology unit.

SAMPLE

Two hundred twenty-nine consecutive fetuses imaged at 12-15 weeks of gestation over a 45-month period.

METHODS

Retrospective analysis of echocardiography and autopsy reports.

MAIN OUTCOME MEASURES

Accuracy of early echocardiography for the detection of abnormalities of the cardiac connections.

RESULTS

Diagnostic images were obtained in 226/229 fetuses (98.7%). Abnormalities of the cardiac connections were detected in 13 fetuses (5.7%) on the initial scan. Where information was available (n = 11), the echocardiographic findings were confirmed at autopsy or postnatally. In two of the 13 cases of congenital heart disease, repeat echocardiography was necessary to provide additional cardiological information. Of the 213 cases in whom a normal initial report was issued, four (1.7%) had congenital heart disease diagnosed later in pregnancy (n = 3) or postnatally (n = 1). Three of these fetuses had haemodynamically insignificant ventricular septal defects and one developed a dilated cardiomyopathy later in gestation.

CONCLUSIONS

Transabdominal fetal echocardiography can be performed at 12-15 weeks of gestation permitting accurate early detection of major congenital heart defects in a high risk population. Some forms of congenital heart disease, usually minor, may not be detectable at such an early stage.

Atrioventricular septal defects diagnosed in fetal life: associated cardiac and extra-cardiac abnormalities and outcome

OBJECTIVES

We sought to establish the outlook for fetuses diagnosed with atrioventricular septal defect (AVSD) prenatally and its relation to additional cardiac, extracardiac and chromosomal abnormalities.

BACKGROUND

Prediction of likely outcome of AVSD presenting prenatally is complicated by the wide variation in associated features.

METHODS

Computerized records from 14,726 pregnancies referred to a fetal cardiology center were reviewed retrospectively. Pathological reports, postnatal records, follow-up inquiries and review of echocardiographic video recordings supplemented analysis of the records for all those with AVSD.

RESULTS

Atrioventricular septal defect was confirmed in 301 fetuses. Eighty-six (39%) of the 218 with known karyotype had trisomy 21, and 21/218 (10%) had other chromosome abnormalities. Right isomerism occurred in 37/301 (12%) fetuses, left isomerism in 62 (20%), mirror image atrial arrangement in 2 (1%), and 200 (67%) had usual arrangement. Atrioventricular septal defect occurred without any other intracardiac abnormality in 155 fetuses (51%). Extracardiac abnormalities and nonkaryotypic syndromes were evident in 40 fetuses (13%, confidence interval [CI] 9.5-17.1%). Uncomplicated cardiac anatomy was significantly associated with the presence of karyotype abnormality (p < 0.0001). Parents opted for termination of pregnancy in 175/298 (58.5%). For the continuing pregnancies, Kaplan-Meier estimates for live birth, survival past the neonatal period and survival to three years were 82% (CI 75.3-88.9%), 55% (CI 46.0%-0/64.3%) and 38% (CI 27.1-48.6%), respectively. Fetal hydrops and earlier year of diagnosis were independent variables with adverse influence on survival.

CONCLUSIONS

Despite some improvements in the outlook for AVSD diagnosed prenatally, the overall prognosis remains considerably poorer than that implied from surgical series. The detection of associated cardiac and extracardiac abnormalities is important in order to give the best indication of the likely outcome when counseling parents.

Nuchal translucency and congenital heart defects: heart failure or not?

OBJECTIVE

To determine whether heart failure is the mechanism underlying the association between increased fetal nuchal translucency and congenital heart defects.

METHODS

Retrospective analysis of the types of congenital heart defect observed in fetuses with increased nuchal translucency and those with normal nuchal scans. Retrospective quantitative analysis of cardiac size and left ventricular ejection fraction in fetuses with ventricular septal defects or the hypoplastic left heart syndrome.

RESULTS

Eighty-three fetuses with congenital heart defects had undergone nuchal screening of which 51 had increased nuchal translucency and 32 had normal nuchal translucency. A wide variety of different congenital cardiac lesions with different hemodynamic effects were observed in fetuses with increased nuchal translucency and those with normal nuchal scans. Defects primarily characterized by left heart obstruction, right heart obstruction and septal defects occurred in both groups. All measurements of cardiothoracic ratio and left ventricular ejection fraction fell within the normal range and there was no significant difference between fetuses with increased nuchal translucency and those with normal nuchal scans.

CONCLUSIONS

No specific type of congenital heart lesion is associated with increased nuchal translucency. The contention that heart failure explains the association between congenital heart defects and increased nuchal translucency is not supported by this study.

Pulmonary atresia with intact ventricular septum: impact of fetal echocardiography on incidence at birth and postnatal outcome. UK and Eire Collaborative Study of Pulmonary Atresia with Intact Ventricular Septum

BACKGROUND

Fetal echocardiography is widely established in the United Kingdom for prenatal diagnosis of congenital heart disease. This may result in a substantial reduction in incidence at birth because of selected termination of pregnancy. The objective of this population-based study was to determine the incidence of pulmonary atresia with intact ventricular septum (PAIVS) at birth, the impact of fetal echocardiography on this incidence, and to compare the outcome of cases with and those without prenatal diagnosis.

METHODS AND RESULTS

From 1991 to 1995, all infants born with PAIVS and all fetal diagnoses in the United Kingdom and Eire were studied. There were 183 live births (incidence 4.5/100,000 live births). The incidence was 4.1 cases per 100,000 live births in England and Wales, 4.7 in Scotland, 6.8 in Eire, and 9.6 in Northern Ireland (P=0.01). There were 86 fetal diagnoses made at a mean of 22.0 weeks of gestation leading to 53 terminations of pregnancy (61%), 4 intrauterine deaths (5%), and 29 live births (34%). The incidence at birth would be 5.6 per 100,000 births in England and Wales, 5.3 in Scotland, and unchanged in Eire and Northern Ireland, if there were no terminations of pregnancy and assuming no further spontaneous fetal deaths (P=0.28). An initial diagnosis of critical pulmonary stenosis was made in 6 cases, at a mean of 22.3 weeks of gestation with progression to PAIVS by 31.4 weeks. Probability of survival at 1 year was 65% and was the same for live-born infants whether or not a fetal diagnosis had been made.

CONCLUSIONS

PAIVS is rare, occurring in 1 in 22,000 live births in the United Kingdom and Eire. Termination of pregnancy has resulted in an important reduction in the live-born incidence in mainland Britain.

Fetal tachycardias: management and outcome of 127 consecutive cases

OBJECTIVE

To review the management and outcome of fetal tachycardia, and to determine the problems encountered with various treatment protocols.

STUDY DESIGN

Retrospective analysis.

SUBJECTS

127 consecutive fetuses with a tachycardia presenting between 1980 and 1996 to a single tertiary centre for fetal cardiology. The median gestational age at presentation was 32 weeks (range 18 to 42).

RESULTS

105 fetuses had a supraventricular tachycardia and 22 had atrial flutter. Overall, 52 fetuses were hydropic and 75 non-hydropic. Prenatal control of the tachycardia was achieved in 83% of treated non-hydropic fetuses compared with 66% of the treated hydropic fetuses. Digoxin monotherapy converted most (62%) of the treated non-hydropic fetuses, and 96% survived through the neonatal period. First line drug treatment for hydropic fetuses was more diverse, including digoxin (n = 5), digoxin plus verapamil (n = 14), and flecainide (n = 27). The response rates to these drugs were 20%, 57%, and 59%, respectively, confirming that digoxin monotherapy is a poor choice for the hydropic fetus. Response to flecainide was faster than to the other drugs. Direct fetal treatment was used in four fetuses, of whom two survived. Overall, 73% (n = 38) of the hydropic fetuses survived. Postnatally, 4% of the non-hydropic group had ECG evidence of pre-excitation, compared with 16% of the hydropic group; 57% of non-hydropic fetuses were treated with long term anti-arrhythmics compared with 79% of hydropic fetuses.

CONCLUSIONS

Non-hydropic fetuses with tachycardias have a very good prognosis with transplacental treatment. Most arrhythmias associated with fetal hydrops can be controlled with transplacental treatment, but the mortality in this group is 27%. At present, there is no ideal treatment protocol for these fetuses and a large prospective multicentre trial is required to optimise treatment of both hydropic and non-hydropic fetuses.

Increased nuchal translucency at 10-14 weeks of gestation as a marker for major cardiac defects

Screening for fetal cardiac defects is traditionally based on the ultrasonographic examination of the four-chamber view of the fetal heart at mid-gestation, which has been shown to identify 26% of major cardiac defects. Pathological studies in fetuses with increased nuchal translucency at 10-14 weeks of gestation, a sonographic marker for chromosomal abnormalities, have shown an association between increased nuchal translucency and congenital abnormalities of the heart. This study reports the prevalence of cardiac defects in 1427 chromosomally normal fetuses with increased nuchal translucency thickness, and examines the potential value of this sonographic marker in screening for major cardiac defects. The diagnosis of cardiac defects was made either by postmortem examination in terminations of pregnancy and intrauterine or neonatal deaths or by clinical examination and appropriate investigations in live births. The prevalence of major cardiac defects was 17 per 1000 (24 of 1427 fetuses) and increased with translucency thickness from 5.4 per 1000 for translucency of 2.5-3.4 mm to 233 per 1000 for translucency of > or = 5.5 mm. These findings suggest that measurement of nuchal translucency thickness at 10-14 weeks may prove to be a useful method of screening for abnormalities of the heart and great arteries in addition to its role in screening for chromosomal defects.

Prenatal diagnosis of 22q11 deletions: a series of five cases with congenital heart defects

We report a series of five patients with congenital heart defects in whom a prenatal diagnosis of 22q11 deletion has been made. The accurate cardiac and cytogenetic diagnoses were made between 20 and 23 weeks' gestation in all cases and the cardiac findings were all confirmed postnatally. The cardiac abnormalities included tetralogy of Fallot with absent pulmonary valve, pulmonary atresia with VSD, common arterial trunk, and left atrial isomerism with double outlet right ventricle. The problems of genetic counselling in these cases are discussed. A recommendation is made to test all fetuses with conotruncal heart abnormalities detected prenatally for a 22q11 deletion, whereas guidelines for other congenital heart disease types are less clear.

Natural history and outcome of aortic stenosis diagnosed prenatally

OBJECTIVE

To document the growth of the left heart structures and outcome of fetuses with aortic stenosis.

DESIGN

Retrospective echocardiographic and clinical study.

SETTING

Tertiary centre for fetal cardiology.

PATIENTS

27 consecutive fetuses with aortic stenosis.

MAIN OUTCOME MEASURES

Survival of affected fetuses. Measurement of left ventricular end diastolic volume (LVEDV), aortic root diameter, and ejection fraction.

RESULTS

Before 25 weeks' gestation, the LVEDV was normal or increased in all cases. In six of eight fetuses studied sequentially, the LVEDV fell across normal centiles. Initial ejection fraction was reduced in 23 fetuses (88%). Before 28 weeks' gestation, the aortic root was normal in all but one case, but after 29 weeks, 11 of 13 fetuses had values below the 50th centile. In two fetuses prenatal aortic valvoplasty was attempted, 10 babies had postnatal interventions, and there were six survivors. Biventricular repair was attempted in eight cases, of whom five survived. A first stage Norwood operation was performed in three babies, of whom one survived. The four fetuses with the highest aortic root z scores had successful biventricular repair. The two fetuses with initially normal ejection fractions survived. Successful biventricular repair was achieved even where the LVEDV was below the 5th centile.

CONCLUSIONS

In aortic stenosis diagnosed prenatally, failure of growth of the left ventricle and aortic root often occurs. The outcome of affected fetuses is better than previously reported. Prenatal echocardiography may assist selection of suitable candidates for biventricular versus Norwood repair.

Outcome of intermittent tachyarrhythmias in the fetus

Persistent fetal tachycardias are known to have an adverse effect on fetal outcome. The outcomes of intermittent fetal tachyarrhythmias over a 12-year period at a tertiary fetal cardiology center were studied. Main outcome criteria included control of arrhythmia and death during the prenatal or postnatal period. A total of 28 fetuses had an intermittent tachyarrhythmia: 4 had intermittent atrial flutter and 24 had supraventricular tachycardia. At the time of presentation 14 fetuses were hydropic, and in 5 of the 14 an arrhythmia had not been noted prior to referral. Of the 28 fetuses, 23 were treated by drug administration to the mother. Control of arrhythmia was achieved in 10 of 11 (91%) nonhydropic fetuses and 8 of 12 (67%) hydropic fetuses, with resolution of hydrops in four cases. In the overall group there was one intrauterine death, two neonatal deaths, and one infant death, all of which occurred in the hydropic group. The arrhythmia recurred postnatally in 11 of 23 (48%) fetuses. We conclude that intermittent tachyarrhythmias may have a deleterious effect on the fetus with a significant risk of death pre- or postnatally. The fetus with nonimmune hydrops should be evaluated for a cardiac cause. Maternal antiarrhythmic therapy is indicated for intermittent fetal tachyarrhythmias. There is a high risk of recurrence of the arrhythmia during infancy, particularly if hydrops was documented during the prenatal period or if Wolff-Parkinson-White syndrome is diagnosed. Fetal echocardiography is a useful tool for diagnosis and for monitoring the progress of the fetus.

Isomerism of the atrial appendages associated with 22q11 deletion in a fetus

There is a strong association between prenatally diagnosed structural heart disease and fetal chromosomal abnormalities. Isomerism of the atrial appendages is an exception to this because the fetal karyotype is usually normal in this condition. A case of atrial isomerism diagnosed antenatally with a normal female karyotype but with a microdeletion of chromosome 22q11 is reported.

Evaluation of three-dimensional ultrasonography and magnetic resonance imaging in assessment of congenital heart anomalies in fetal cardiac specimens

In this observational study, multiplanar three-dimensional ultrasound images were reconstructed from tomographic views obtained by scanning seven cadavaric fetal hearts with various congenital heart defects. Comparisons were made with multiplanar three-dimensional magnetic resonance imaging (MRI) of the hearts. Good-quality echocardiographic images were obtained in all but one of the fetal hearts. Multiplanar as well as three-dimensional reconstructions were possible and allowed accurate assessment of complex cardiac defects. Overall, the MRI projections had better image quality and revealed more structural details than the sonographic views, although both imaging modes showed the same cardiac anatomical abnormalities. Our initial results demonstrate that simultaneous multiplanar display of cross-sectional echocardiographic views can be performed to provide three-dimensional images of the fetal heart, demonstrating structural cardiac malformation. However, the clinical application of three-dimensional fetal echocardiography is at present limited by the time required for image data acquisition and the need for accurate temporal and positional gating in the living fetus.

Prenatal detection and progression of right coronary artery to right ventricle fistula

Prenatal diagnosis of a congenital coronary artery fistula between the right coronary artery and right ventricle was made by colour Doppler echocardiography at 20 weeks of gestation. Its progression was monitored by serial echocardiography throughout pregnancy and postnatally.

Incidence of congenital heart defects in fetuses of diabetic mothers: a retrospective study of 326 cases

The aim of this study was to quantify the risk of congenital heart disease in diabetic mothers referred for fetal echocardiography. Of 326 diabetic pregnancies seen over a 5-year period, ten (3.1%) resulted in a fetus with congenital heart disease. Nine (90%) of the ten cardiac lesions were identified prenatally, but one fetus had a ventricular septal defect that was overlooked antenatally. Postnatal follow-up was obtained in 312 cases (95.7%). Prenatal echocardiographic examinations were performed at 18-38 weeks of gestation (median 25 weeks) and the median gestational age at diagnosis of congenital heart disease was 22 weeks (range 19-30 weeks). Following the detection of a severe cardiac anomaly, the pregnancy was terminated in three cases. Of the seven continuing pregnancies, two resulted in spontaneous intrauterine death and two babies died within the first 6 months of life. The three survivors are clinically well, but one has required postnatal catheter intervention. Our results confirm that diabetic women are at increased risk of having a baby with congenital heart disease and detailed fetal echocardiography should therefore be offered to all diabetic women during pregnancy.

Echocardiographic-anatomical correlations in aorto-left ventricular tunnel

OBJECTIVE

To investigate the echocardiographic, morphological, and histological appearances of aorto-left ventricular tunnel observed in four fetal hearts and compare the findings with those reported in older patients with the malformation.

BACKGROUND

Previous studies have concentrated on clinical features of the malformation from birth to adult life and have speculated on either its embryological formation or its acquisition during late intrauterine life. The presentation of a large series of cases in fetal life is a unique opportunity to study the malformation at an early stage in its natural course.

METHODS

A retrospective study was performed of four cases of aorto-left ventricular tunnel discovered among 872 cases of congenital abnormalities diagnosed at a tertiary centre for fetal echocardiography. Detailed echocardiographic and anatomical observations were made of the malformation as identified during fetal life. The precise anatomical arrangement was determined and compared with previous descriptions found in journals published in English.

RESULTS

In fetal life, as after birth, the malformation is characterised by enlargement and hypertrophy of the left ventricle, enlargement of the aortic root, and free regurgitation at the level of the aortic valve. Anatomical abnormalities are found at the aortic ventriculoarterial and sinutubular junctions as well as in the intervening aortic wall. These are unrelated to necrosis, ischaemia, or the presence of mucopolysaccharides.

CONCLUSIONS

The lesion is a developmental abnormality that should be reliably diagnosed by fetal echocardiography combined with colour flow Doppler echocardiography during the mid-trimester. The exact anatomical relations clarified by this study are pertinent to diagnosis and subsequent surgical correction.

Congenital heart disease in spondylothoracic dysostosis: two familial cases

Two familial cases of spondylothoracic dysostosis are reported. Both cases had severe congenital heart disease in addition to the skeletal malformations which are characteristic of the condition.

Prospective diagnosis of 1,006 consecutive cases of congenital heart disease in the fetus

OBJECTIVE

This report describes our experience with fetal congenital heart disease since 1980.

BACKGROUND

Knowledge and expertise in the diagnosis, management and natural history of fetal congenital heart disease is increasingly demanded by both obstetricians and parents. The analysis of a large series should help the pediatric cardiologist to provide this service.

METHODS

The notes of 1,006 patients, where a prospective diagnosis of fetal congenital heart disease was made, were reviewed. The reason for referral, the diagnosis made, the accuracy of diagnosis, the fetal karyotype and the outcome of the pregnancy were noted. The cases were grouped into malformation categories, and the spectrum of disease seen was compared with that found in infants.

RESULTS

Most fetal cardiac anomalies are now suspected by the ultrasonographer during obstetric scanning. A different incidence of abnormalities is seen compared with that expected in infants. Chromosomal anomalies were more frequent in the fetus than in live births. The accuracy of diagnosis was good. The survival rate after diagnosis was poor because of frequent parental choice to interrupt pregnancy and the complexity of disease.

CONCLUSIONS

A large experience with fetal congenital heart disease allows the spectrum of disease to be described with accuracy and compared with that in infancy. Knowledge of the natural history of heart malformations when they present in the fetus allows accurate counseling to be offered to the parents. If the trend in parental decisions found in this series continues, a smaller number of infants and children with complex cardiac lesions will present in postnatal life.

Coarctation of the aorta: difficulties in prenatal diagnosis

OBJECTIVE

To formulate echocardiographic criteria for the prenatal diagnosis of coarctation of the aorta.

DESIGN

A retrospective study examining the echocardiograms of fetuses with a verified aortic arch abnormality and those in whom the diagnosis was suspected prenatally but was not subsequently confirmed.

SETTING

Tertiary referral centre for fetal echocardiography.

PATIENTS

87 fetuses in whom the diagnosis of coarctation was correctly made in 54, suspected but unproved in 24, and overlooked prenatally in nine.

MAIN OUTCOME MEASURES

Measurements of left and right ventricular size, the diameters of the great arteries, the diameters of the left and right atrioventricular valvar orifices, the appearance of the aortic arch, and the direction of the flow of blood across the foramen ovale.

RESULTS

Measurements of the ventricular widths, diameters of the great arteries, or the diameters of the atrioventricular valvar orifices, did not allow clear distinction between cases that definitely had a coarctation and those in whom the diagnosis was unproved. The appearance of the aortic arch, particularly in the horizontal projection, was more helpful in distinguishing cases of coarctation, although this also was not always diagnostic. A predominantly left to right shunt across the foramen ovale was detected more often in cases with a substantiated coarctation (58%) than in those with an unproved diagnosis (12%).

CONCLUSIONS

The most severe forms of coarctation are associated with relative hypoplasia of the left heart structures compared with the right and a correct diagnosis can be made in early pregnancy. The milder forms of coarctation, however, are consistent with a normal early fetal echocardiogram. In late pregnancy it may be impossible to exclude coarctation categorically as the right heart structures may appear larger than the left in the normal fetus. Thus although a combination of echocardiographic features can correctly identify aortic arch anomalies in the fetus, none either alone or in combination, could clearly distinguish between real and false positive cases, particularly in late gestation.

Potential impact of population screening for prenatal diagnosis of congenital heart disease

The potential impact of prenatal screening for the detection of congenital heart disease (CHD) was assessed by prospective analysis of 428 consecutive infant admissions to a supraregional centre; 28 (6.5%) did not have CHD and were excluded from analysis. Of the 400 cases with CDH, 396 (99%) underwent fetal ultrasonography but scanning was performed only before 18 weeks' gestation in 200 (50%). One hundred and forty nine (37%) of all cardiac abnormalities and 149/283 (53%) of severe abnormalities were considered to be detectable prenatally in a screening echocardiographic four chamber view had this technique been used. Prenatal diagnosis of severe CHD actually occurred in only eight (2%) cases and was after 30 weeks' gestation in all. There were 181/347 (52%) of all mothers and 177/253 (70%) of the subgroup with severe abnormalities who expressed an opinion volunteered their preference for termination of pregnancy if mid-trimester diagnosis had been available. Mid-trimester detection of congenital heart disease rarely occurs at present despite fetal ultrasound scanning in almost all pregnancies. More than half of all severe congenital heart defects seen in infancy are potentially detectable by screening. Major training at primary scan level and modification of the timing of existing fetal anomaly scanning would be required for a screening programme to be effective.

Normal fetal cardiac measurements derived by cross-sectional echocardiography

Cardiac structures have been measured in normal fetuses by cross-sectional echocardiography to establish a range of normal values. Gestational ages varied from 16 weeks to term. The cardiac structures measured were left and right ventricular width (n = 337), aortic root diameter (n = 296), pulmonary artery diameter (n = 312), mitral valve orifice (n = 159), and tricuspid valve orifice (n = 161). The lengths of the left and right ventricles were measured in 100 fetuses. Normal ranges were constructed using real-time ultrasound images which can be readily used in routine practice. Measurement of cardiac structures is an aid to the study of cardiac abnormalities and the availability of normal ranges of measurements of fetal cardiac structures may help to confirm and define suspected cardiac malformation during routine screening.

Screening for congenital heart disease prenatally. Results of a 2 1/2-year study in the South East Thames Region

OBJECTIVE

To assess the efficacy of four chamber view examination, during routine obstetric scanning, in the prenatal detection of fetuses with congenital heart disease.

DESIGN

Prospective observational study.

SETTING

Ten obstetric ultrasound units in the South East Thames Region.

SUBJECTS

All pregnant women attending for routine obstetric ultrasound examination.

INTERVENTION

Ultrasonographers performing routine ultrasound examinations were taught to obtain, and correctly interpret, the four chamber view of the fetal heart. When this view could not be achieved adequately, an attempt was made to identify a reason for failure and, if possible, to arrange a repeat scan. All suspected abnormalities were referred to a specialized unit.

MAIN OUTCOME MEASURES

Numbers of true abnormalities detected or overlooked, and the number in whom abnormality was suspected incorrectly.

RESULTS

Over a 2.5-year period, 69% of the known number of cardiac lesions associated with an abnormality of the four chamber view were detected prenatally during the routine obstetric scan, 10% were identified as a result of referal for other high-risk factors and 21% were overlooked. The overall positive predictive value in the 10 obstetric units was 36%.

CONCLUSIONS

Prenatal screening for some forms of major congenital heart disease is possible by including examination of the four chamber view of the fetal heart in routine obstetric scans. However, there are important limiting factors that will influence the success of abnormality detection and must be taken into account if screening is to be effective nationwide.

Prognosis in fetal diaphragmatic hernia

The reported mortality for prenatally detected congenital diaphragmatic hernia is high. Polyhydramnios and presentation in early pregnancy have been suggested as high-risk factors adversely affecting outcome. We retrospectively reviewed 55 cases of congenital diaphragmatic hernia diagnosed prenatally in our unit. There was an overall mortality of 73%. The mortality in cases with presentation before 25 weeks' gestation was 74%, if the cases resulting in termination of pregnancy are excluded, compared with a mortality of 60% in those seen after this gestational age. Underdevelopment of left-sided cardiac structures was found to be a helpful prognostic factor. We were unable to confirm the predictive nature of hydramnios. Associated chromosomal anomalies were found in two fetuses and major congenital heart disease in nine. Although diagnosis before 25 weeks' gestation is associated with a higher mortality than in cases detected later, it is not universally fatal. If congenital heart disease and chromosomal anomalies are excluded and there is little or no evidence of left heart underdevelopment, the odds for survival will improve. This should be taken into account when the management of these cases is planned.

Prognosis in fetal tetralogy of Fallot

The outcome in a series of 23 cases of tetralogy of Fallot diagnosed prenatally was compared to published figures for this condition when (a) identified postnatally or (b) treated surgically. There was a marked difference in the survival between these groups, with the highest mortality (75%) occurring when the diagnosis had been made prenatally. The high incidence of chromosomal and extracardiac anomalies in this group (60%) largely accounted for the discrepancy. This, and the potential for progressive changes in the anatomy of the defect during pregnancy, must be taken into account by the pediatric cardiologist offering prognosis in early pregnancy.

Left ventricular dysfunction in the fetus: relation to aortic valve anomalies and endocardial fibroelastosis

OBJECTIVE

To examine the relation between a characteristic form of left ventricular dysfunction in the fetus and abnormalities of the aortic valve and endocardial fibroelastosis of the left ventricle.

DESIGN

A retrospective study to examine the correlation between echocardiographic findings in the fetus and postnatal or necropsy findings.

SETTING

Tertiary referral centre for fetal echocardiography.

PATIENTS

Thirty fetuses showing a characteristic echocardiographic picture of left ventricular dysfunction.

MAIN OUTCOME MEASURES

The relation between the prenatal echocardiographic features and the postnatal and necropsy findings.

RESULTS

At presentation the size of the left ventricular cavity was normal or enlarged in all cases. The measurements of the orifice of the aortic root and mitral valve were either normal or small for the gestational age. The echocardiographic diagnosis made at presentation was critical aortic stenosis in all cases. At necropsy or postnatal examination the aortic valve was dysplastic and stenotic in 15 cases and the left ventricle had become hypoplastic in one of these. Aortic atresia was present in seven patients, three of whom had a hypoplastic left ventricle. In six patients the aortic valve was bicuspid although not obstructive. One of these patients had hypoplasia of the aortic arch and one had a hypoplastic left ventricle but in the remaining four patients endocardial fibroelastosis of the left ventricle was the only abnormality found. No follow up information was available in two. Of 26 patients for whom there was postmortem information, 24 had evidence of some degree of endocardial fibroelastosis of the left ventricle. Sequential observations showed that five cases developed into the hypoplastic left heart syndrome.

CONCLUSIONS

This type of left ventricular dysfunction in the fetus is the result of an overlap of diseases, including primary left ventricular endocardial fibroelastosis, critical aortic stenosis, and the hypoplastic left heart syndrome.

Is the ultrasound definition of fluid collections in non-immune hydrops fetalis helpful in defining the underlying cause or predicting outcome?

The ultrasound findings in 132 patients with non-immune hydrops referred for echocardiographic assessment were retrospectively reviewed. Structural assessment was combined with evaluation of pleural and pericardial effusions, ascites and skin edema. Patients were divided into groups based on the underlying etiology of hydrops. Seventy patients were found to have cardiac abnormalities, including 45 with structural heart disease. Other causes included. chromosomal anomalies, infection, extra-cardiac anomalies, genetic syndromes and, in 40 patients, unknown cause. Analysis of patterns of fluid accumulation revealed a significantly decreased incidence of pleural effusions and ascites in fetuses with an underlying cardiac abnormality. Cardiomegaly based on the cardio-thoracic ratio was significantly more frequent in the cardiac group. When patients were grouped by outcome, no pattern of fluid distribution was found to be characteristic for survival or death. We conclude that ultrasound definition of fluid collections in non-immune hydrops may be helpful in predicting the underlying cause of the hydrops, although there are no specific patterns predictive of outcome.

Hypoplastic left heart syndrome: effects of fetal echocardiography on birth prevalence

Hypoplastic left heart syndrome was diagnosed prenatally and confirmed in 105 fetuses since 1983 at a regional referral centre. An increased detection rate since 1988 is probably related to increased experience in the use of a four-chamber view of the fetal heart during routine obstetric ultrasound scanning. When the diagnosis was made sufficiently early, most parents chose to terminate the pregnancy after the prognosis and surgical options were explained. By contrast, after an increase in the mid 1980s, since 1988 there has been a striking fall in the number of newborn babies with hypoplastic left heart syndrome treated at a supraregional referral centre. More widespread use of four-chamber cardiac screening during routine fetal ultrasonography may reduce the number of newborn babies with hypoplastic left heart syndrome--a factor which should be taken into account when the likely requirements for neonatal cardiac transplantation facilities are calculated.

Factors influencing the outcome of congenital heart disease detected prenatally

The diagnosis of structural heart disease before birth is associated with a poor prognosis. Of 222 continuing pregnancies seen in a 10 year period, there has been a 79% mortality. This is inconsistent with published results and current concepts of the outcome for children with cardiac malformation. Of the 222, death occurred in intrauterine life in 57, 87 died as neonates, and 31 in infancy or childhood. There are 47 survivors of whom only five have survived beyond 4 years. Factors influencing the outcome in these cases were examined further. A high mortality was associated with the presence of extracardiac anomalies in 71 (32%) and prenatal cardiac failure in 28 (13%). As many patients were referred for these reasons, referral methods preferentially select patients with a different range of heart disease from that seen postnatally. In addition, some forms of heart disease progress in severity during fetal life. Those involved in the management and counselling after diagnosis of heart disease in early pregnancy must be aware of the additional prenatal factors influencing prognosis and allow for them in making predictions of outcome.

Chromosomal anomalies in fetal congenital heart disease

A series of 467 cases of congenital heart disease detected in prenatal life were analyzed to identify the forms of cardiac malformation associated with karyotypic defects and to calculate the incidence of chromosomal abnormalities associated with such malformations. Of these, 77 were proved to have chromosomal anomalies although not all were karyotyped. The results were analyzed in two ways. First, the whole series of 77 cases was examined in order to describe the form of congenital heart disease found in association as, although many cases were forms of heart disease known to be associated with chromosomal defects, several were unexpected. In many cases which proved positive, there were other abnormal findings on ultrasound, further suggesting a high likelihood of a chromosomal defect. Some cardiac defects, however, such as atrial isomerism or transposition of the great arteries, were not associated with trisomies. The second part of the study examined in detail the records of 124 cases of congenital heart disease seen in 1989, as these were more completely documented than the previous cases. No chromosomal anomaly was therefore thought to be missed. Of this group, 20 (16%) proved positive. This is a higher rate than would be expected in an unselected population of live births. The difference between prenatal and postnatal life can be accounted for by the increased rate of spontaneous fetal loss in those with chromosomal defects. We conclude that, because of the high rate of chromosomal anomaly, all continuing pregnancies where congenital heart disease has been found in the fetus should be karyotyped unless specific types of heart defect which are rarely associated are confidently defined.

Flecainide in the treatment of fetal tachycardias

Fourteen mothers were treated with flecainide for fetal atrial tachycardias associated with intrauterine cardiac failure. Twelve of the 14 fetuses responded by conversion to sinus rhythm. One of the 12 fetuses subsequently died in utero. The remaining fetuses suffered no morbidity and were alive and well 3 months to 2 years after delivery. The two fetuses in whom atrial tachycardia did not convert with flecainide were successfully treated with digoxin. These results compare favourably with previous forms of antiarrhythmic treatment. After recent reports of the side effects of flecainide treatment, however, it has been advised that this drug should be confined to high risk patients and those with life threatening arrhythmias. The use of flecainide for fetal arrhythmias should be limited to patients with severe fetal hydrops and supraventricular tachycardias. It should not be the first drug of choice in atrial flutter.

The accuracy of fetal echocardiography in the diagnosis of congenital heart disease

The accuracy of the echocardiographic diagnosis of fetal heart disease in an experienced centre was evaluated by analysing the results achieved during 1987 at the Perinatal Cardiology Unit, Guy's Hospital. In this one year, 978 high-risk patients were referred for fetal echocardiography. Of these, 74 cases were found to have cardiac malformation, 69 of which were predicted from the prenatal study. Of the 69, the autopsy specimen was available for correlative purposes in 41 cases. A postnatal echocardiogram was performed by us in a further 15 cases. The result of autopsy or of a postnatal echocardiogram was obtained from another hospital in 7 cases. Postmortem was refused in 5 cases, while one further case remains alive but has not had a postnatal echocardiogram. Close correlation was achieved between the predicted echocardiographic diagnosis and the anatomical results. Some minor errors in the complete interpretation of a defect were found, particularly in those fetuses in whom image quality was poor, due to early (less than 20 weeks) or late (greater than 34 weeks) gestation or to maternal obesity. Difficulty in echocardiographic interpretation was also experienced in unusual defects. There was one false positive prediction of coarctation of the aorta. One major (total anomalous pulmonary venous drainage) and 5 minor abnormalities (two atrial and three ventricular septal defects) detected after birth were overlooked on the fetal study. Although the echocardiogram in prenatal life is not as accurate as it can be postnatally, with suitable experience a high degree of precision can now be achieved.