Molecular cloning of human GATA-6 DNA binding protein: high levels of expression in heart and gut.

Human GATA-6 has been cloned from foetal heart by a combination of PCR-based methods and cDNA library screening. The 3.8 kbp cDNA has a coding sequence of 1347 bp the 449 aa protein is virtually identical in the two zinc-finger binding domains to other human GATA sequences, but varies considerably in the amino and carboxy terminal regions. The sequence shows greatest similarity to GATA-6-like sequences from rat, mouse, chicken and Xenopus. Northern analysis and in situ hybridisation show that GATA-6 is expressed at high levels in human adult and foetal heart as well as in gut derivatives. It is postulated that GATA-6, in concert with GATA-4, plays a crucial role in the regulation of cardiac differentiation.

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.

Fetal echocardiography in trisomy 18.

BACKGROUND: Previously reported pathological series suggest that cardiac malformations are universal in trisomy 18. We examined our experience of fetal echocardiography in trisomy 18 for comparison. METHODS: Of 255 fetuses with trisomy 18 detected in our centre between January 1999 and June 2004, 174 were evaluated using fetal echocardiography. Our results were compared to four previous echocardiographic and four autopsy series, comprising 89 and 110 patients, respectively. RESULTS: Of these 174 fetuses, 114 were examined between 10 and 14 weeks gestation and the remainder between 15 and 33 weeks. An increased nuchal translucency measurement was the reason for referral in most of the early cases and extracardiac anomalies in the remainder. Images were non-diagnostic in 12 cases (7%), all examined at <15 weeks gestation. Abnormal cardiac findings were detected in 118 of the remaining 162 fetuses (73%), including 15 with functional anomalies. The various heart malformations included ventricular septal defects, tetralogy of Fallot, left heart disease, and atrioventricular septal defects. In all series used for comparison, a similar diversity of disease was seen. In pathological series of trisomy 18, structural heart malformations were found in all cases, but some had lesions which would not be detectable echocardiographically in the fetus. CONCLUSION: Abnormal cardiac findings are detectable echocardiographically in the majority of cases of trisomy 18 examined during fetal life, but not in all. A wide spectrum of heart defects is seen. Diagnosis of heart malformations can be made reliably, even in the first trimester at the time of nuchal translucency measurement.

Effect of introducing balloon dilation of native aortic coarctation on overall outcome in infants and children.

The outcome of 40 consecutive newborns and children with normal cardiac connections presenting with unoperated (i.e., no previous surgical or balloon dilation treatment) aortic coarctation since the introduction of balloon dilation as a treatment option (group A) was compared retrospectively with that of a similar cohort of 38 patients (group B) presenting in the period immediately before the introduction of balloon dilation. Group A consisted of 18 newborns (< 30 days) and 22 children and Group B consisted of 20 newborns and 18 children. In group A, 30 patients had balloon dilation but 10 underwent surgery because of parental preference, unfavorable anatomy or for logistic reasons. Group B had conventional surgical repair by various methods. All patients were followed up clinically by Doppler echocardiography and, when possible, by magnetic resonance imaging. Repeat cardiac catheterization was only performed in those with suspected recoarctation. Survival and freedom from reintervention were investigated using Kaplan-Meier analysis. Patients of all ages in group A and those who had balloon dilation were at higher risk for reintervention (25 and 30%, respectively, at 1 year) than those in group B or those who had surgery (20 and 18%, respectively, at 1 year). Mortality was not significantly different between groups A and B, but there were 2 neonatal deaths directly attributable to the dilation procedure. Two patients developed aneurysms after dilation. Balloon dilation is an effective treatment for unoperated coarctation, but the recoarctation rate appears to be higher than for surgery.

Implications of bidirectional flow in the great arteries at the 11-14-week scan.

OBJECTIVE: To determine the implications of a bidirectional Doppler flow pattern detected in one or both of the fetal great arteries in the first trimester. METHODS: Database records were reviewed for cases of bidirectional flow found on fetal echocardiography performed at less than 15 weeks of gestation between January 1999 and October 2006 inclusive. Bidirectional flow consisted of antegrade flow in systole and retrograde flow in diastole. Data including indication for fetal echocardiography, gestational age at diagnosis, the anatomical features, karyotype, nuchal translucency measurement and outcome were collected. RESULTS: From almost 2500 scans, bidirectional flow was detected in a total of 15 fetuses. The abnormal flow pattern was confined to the aorta in four, to the pulmonary artery in four, and was present in both great arteries in a further seven fetuses. Eight of the 15 fetuses had regurgitation at one or both atrioventricular valves. Additional cardiac abnormalities were detected by ultrasound in eight cases. Of the 13 cases for which the karyotype was known, 12 were abnormal and five of these had trisomy 18. None of the fetuses survived. There were two intrauterine deaths and 13 terminations of pregnancy. CONCLUSION: Bidirectional flow in one or both great arteries is an unusual finding at the first-trimester scan and must be distinguished from the retrograde flow occurring only in systole in duct-dependent heart defects. It carries a poor prognosis, which is a consequence of both the high chance of underlying chromosomal abnormality and the hemodynamic compromise associated with severe arterial valve regurgitation.

Tetralogy of Fallot in the fetus in the current era.

OBJECTIVES: To compare the spectrum of tetralogy of Fallot detected recently in fetal life with that in previous reports of prenatal and postnatal experience. METHODS: All cases of tetralogy of Fallot, including those with pulmonary atresia, diagnosed between 1998 and 2005 inclusive were identified. Additional data for the 129 cases were collected, including associated congenital heart malformations, nuchal translucency measurement, karyotype and outcome. RESULTS: The most common reason for referral was a suspicion of heart malformation at the routine obstetric ultrasonography scan and referrals increased during the study period. The mean gestational age at diagnosis was 20.6 weeks. The nuchal translucency measurement was above the 95th centile in 37 (47%) of the 78 fetuses in which it had been measured, and in 19/37 of the chromosomally normal fetuses. Of 112 fetuses with chromosomal analysis, 55 (49%) had anomalies, including 22q11 microdeletion in 15. There were additional extracardiac malformations in 65/129 cases (50%) and additional cardiac malformations in 73 (57%). In 70/129 (54%) cases, the parents chose termination of pregnancy. Overall survival to date in the continuing pregnancies is 77%. CONCLUSIONS: Tetralogy of Fallot is increasingly recognized during routine fetal obstetric scanning. However, the spectrum of disease detected in the fetus remains biased towards those cases with extracardiac malformations and those with complex disease. As a result, even in the current era, the prognosis for the whole group of fetal cases under the diagnostic heading of tetralogy of Fallot continues to be much less favorable than would be expected of a postnatal series.

Right aortic arch in the fetus.

OBJECTIVE: To examine our experience of the detection of a right aortic arch in the fetus over an 8-year period. METHODS: Between February 1998 and December 2005, all patients prospectively diagnosed with a right aortic arch at our center were identified from our database and the videotape reviewed. In addition, the videotapes of 300 normal and 110 abnormal arbitrarily selected fetal echocardiograms, as well as 123 cases of tetralogy of Fallot and nine of a common arterial trunk were reviewed. Data including indication for fetal echocardiography, gestational age at diagnosis, karyotype, nuchal translucency measurement and outcome were collected. RESULTS: A right aortic arch was diagnosed prospectively in 55 fetuses and in a further 20 on retrospective videotape review. There were 21 examples of isolated aortic arch and four thought to have a double arch. A right arch was found in association with additional intracardiac malformations in 50 cases. The detection rate of a right aortic arch increased over the study period. The majority of patients were referred for a suspicion of congenital heart disease on obstetric scanning. Mean gestational age at diagnosis was 21 weeks. The karyotype including 22q11 status was known in 45/75 cases. There were 23 confirmed karyotypic anomalies, 12 of which were 22q11 deletions, occurring in 2/25 of the isolated group and 10/48 of the complex group, with a further two complex cases that were likely to have had 22q11 microdeletions. There were 29 pregnancy interruptions, four intrauterine deaths, 31 live births, four neonatal deaths and three patients lost to follow-up. The remaining four pregnancies are continuing. Of the four with suspected double arch, three were confirmed postnatally. CONCLUSION: The diagnosis of a right-sided aortic arch can be made by fetal echocardiography, either as an isolated lesion or in association with other cardiac malformations, from as early as 12 weeks' gestation. It can be difficult to distinguish from a double arch. Its increasing incidence over time in our series probably indicates that the diagnosis was previously overlooked. Karyotyping in the absence of other abnormal findings may be unnecessary in every case, but establishment of 22q11 microdeletion status in those cases with other anomalies is important.

Relationship between nuchal translucency thickness and prevalence of major cardiac defects in fetuses with normal karyotype.

OBJECTIVE: To define the prevalence of major cardiac defects according to nuchal translucency (NT) thickness at the 11 to 13 + 6-week scan in fetuses with normal karyotype. METHODS: Specialist fetal echocardiography was carried in 6921 fetuses with normal or presumed normal karyotype at a median gestation of 20 (range 12-35) weeks. The indications for fetal echocardiography were increased NT thickness (n = 3444), detailed second-trimester scan either for assessment of risk of chromosomal abnormalities (n = 2980) or previous or family history of fetal defects (n = 497). The cardiac defects were grouped into six functional categories: septal defect, left inflow obstruction, right inflow obstruction, left outflow obstruction, right outflow obstruction and other. RESULTS: Major cardiac defects were identified in 132 (19.1 per 1000) fetuses and the prevalence increased with fetal NT thickness from 4.9 per 1000 in those with NT below the median, to 8.7 for NT between the median and less than the 95th centile, 18.2 for NT between the 95th and 99th centiles, and exponentially thereafter to 35.2, 64.4 and 126.7 for respective NTs of 3.5-4.4 mm, 4.5-5.4 mm and > or = 5.5 mm. There was no obvious difference in the distribution of NT in the different types of cardiac defects. CONCLUSIONS: The prevalence of major cardiac defects increases exponentially with fetal NT thickness and in fetuses with NT of 3.5 mm or more it is higher than in pregnancies with a family history of cardiac defects.

Likelihood ratio for trisomy 21 in fetuses with tricuspid regurgitation at the 11 to 13 + 6-week scan.

OBJECTIVE: To determine the likelihood ratio for trisomy 21 in fetuses with tricuspid regurgitation at the 11 to 13 + 6-week scan. METHODS: Fetal echocardiography was carried out by specialist pediatric cardiologists in 742 singleton pregnancies at 11 to 13 + 6 weeks' gestation and pulsed wave Doppler was used to ascertain the presence or absence of tricuspid regurgitation. To avoid confusion with other adjacent signals, a strict definition of tricuspid regurgitation was used, in that it had to occupy at least half of systole and reach a velocity of over 80 cm/s. The fetal crown-rump length (CRL) and the nuchal translucency (NT) thickness were measured and the presence of any congenital heart abnormality noted. Follow-up of the pregnancy was carried out to determine the presence of chromosomal abnormalities. The likelihood ratio for trisomy 21 in fetuses with and without tricuspid regurgitation was determined. RESULTS: The tricuspid valve was successfully examined in 718 (96.8%) cases. Tricuspid regurgitation was present in 39 (8.5%) of the 458 chromosomally normal fetuses, in 82 (65.1%) of the 126 with trisomy 21, in 44 (53.0%) of the 83 with trisomy 18 or 13, and in 11 (21.6%) of the 51 with other chromosomal defects. The prevalence of tricuspid regurgitation was also associated with fetal CRL, delta NT and the presence of cardiac defects. Logistic regression analysis, irrespective of cardiac defects, demonstrated that in the chromosomally normal fetuses significant independent prediction of the likelihood of tricuspid regurgitation was provided by fetal delta NT (odds ratio (OR), 1.26; 95% CI, 1.34-1.41; P < 0.0001), while in trisomy 21 fetuses prediction was provided by CRL (OR, 0.94; 95% CI, 0.89-0.99; P = 0.021). The likelihood ratio for trisomy 21 for tricuspid regurgitation was derived by dividing the likelihood in trisomy 21 by that in normal fetuses. In the chromosomally normal fetuses, the prevalence of tricuspid regurgitation in those with cardiac defects was 46.9% and 5.6% in those without cardiac defects, and the likelihood ratio of tricuspid regurgitation for cardiac defects was 8.4. CONCLUSION: At 11 to 13 + 6 weeks' gestation, there is a high association between tricuspid regurgitation and trisomy 21, as well as other chromosomal defects. The prevalence of tricuspid regurgitation increases with fetal NT thickness and is substantially higher in those with, than those without, a cardiac defect.

Rapid diagnosis of the cause of pneumoperitoneum in ventilated asthmatic children.

Two asthmatic children developed a pneumoperitoneum whilst being mechanically ventilated. A quick and accurate diagnosis as to the cause of the pneumoperitoneum was made by analysing the partial pressure of oxygen in the intraperitoneal free gas. This analysis helped to diagnose an intestinal perforation in one child and an air leak from lung barotrauma in the other. There was minimal delay in the surgical treatment of the child with intestinal perforation and in the other, an unnecessary laparotomy was avoided.

Perioperative haemodynamic effects of an intravenous infusion of calcium chloride in children following cardiac surgery.

Twelve children received an infusion of 10% calcium chloride 0.1 ml/kg to a maximum dose of 5 ml, infused over 5 min, following open heart surgery. Blood ionized calcium, systemic arterial pH, cardiac index, mean systemic arterial blood pressure and systemic vascular resistance index were measured at baseline and repeated 20 and 40 min following completion of the infusion. There was considerable overlap, with no significant differences in the response to the calcium chloride infusion between children with ionized hypocalcaemia (< 1.1 mmol/l) and those with ionized normocalcaemia when its effect on percentage change in either the haemodynamic or biochemical measurements was assessed (p > 0.2 for all measurements; Mann-Whitney). For this reason they were treated as a single group. Significant changes from baseline were noted in mean systemic arterial pressure (p < 0.02), cardiac index (p < 0.01) and systemic vascular resistance index (p < 0.01) after completion of the calcium chloride infusion when analysed using Friedman's two-way analysis of variance. A significant increase in mean systemic arterial blood pressure occurs after an infusion of 10% calcium chloride as a direct result of an increase in the systemic vascular resistance index with a concomitant decrease in cardiac index.

Doppler assessment of cardiac function at 11-14 weeks' gestation in fetuses with normal and increased nuchal translucency.

OBJECTIVE: To investigate cardiac dysfunction as a potential underlying mechanism for increased nuchal translucency (NT) in fetuses with chromosomal abnormality or heart defects. METHODS: Myocardial performance index (MPI) and atrioventricular valve E/A ratios for both sides of the heart were measured by Doppler echocardiography in fetuses at 11-14 weeks' gestation. The study groups consisted of 159 normal control fetuses, 199 otherwise normal fetuses but with increased NT > or = 4 mm, 142 fetuses with trisomy 21, 58 with trisomy 18, 19 with trisomy 13, 37 with Turner's syndrome and 24 with isolated heart defects. Groups were compared using Student's t-test and confidence intervals for differences between groups were calculated. RESULTS: Otherwise normal fetuses with increased NT showed no difference in any of the cardiac Doppler parameters from normal controls. Mean E/A ratio was slightly but significantly increased in trisomy 21 fetuses compared with normal controls (0.604 vs. 0.578 on the right, P = 0.011; 0.581 vs. 0.542 on the left, P = 0.0001). E/A ratio was not significantly different between any of the other groups and the normals but there was a small increase in absolute E-wave velocity in trisomy 18 fetuses. MPI was significantly decreased in trisomy 21 fetuses, (0.330 vs. 0.378, P = 0.002 on the left) and also in Turner's syndrome fetuses (0.301 vs. 0.352 on the right, P = 0.04; 0.320 vs. 0.378 on the left, P = 0.034) implying better performance, but not in the other groups. CONCLUSIONS: The magnitude and/or direction of the differences shown do not support a major role for cardiac functional abnormality in the development of NT. Important cardiac dysfunction could not be demonstrated in association with increased NT in normal or abnormal fetuses.

Tricuspid regurgitation in the diagnosis of chromosomal anomalies in the fetus at 11-14 weeks of gestation.

OBJECTIVE: To analyse patient data to elucidate the apparent association between an abnormal karyotype and tricuspid regurgitation found during fetal echocardiography at early gestations. SETTING: Tertiary referral centre for fetal medicine and cardiology. METHODS: Fetuses between 11 and 14 weeks' gestation were selected for detailed echocardiography. Referral reasons were increased nuchal translucency, a suspected cardiac or extracardiac malformation, and a family history of cardiac malformation. INTERVENTION: The fetus was imaged transabdominally. The four chamber view, outflow tracts, arterial duct, and aortic arch were assessed on cross sectional imaging and colour flow mapping. Pulsed Doppler of the atrioventricular valves was recorded if possible. Subsequently, the fetal karyotype was ascertained by chorionic villous sampling. RESULTS: Pulsed Doppler recording of the tricuspid valve was obtained for 262 fetuses. Tricuspid regurgitation was present in 70 (27%) of these, of whom 58 (83%) proved to have karyotype anomalies. In contrast, 68 (35%) of those without tricuspid regurgitation were found to have karyotype anomalies (95% confidence interval 36% to 59%, p < 0.001). Structural heart defects were detected in 34 of the 58 (59%) with tricuspid regurgitation and in 22 (32%) of those without. The chromosome defect most frequently found to be associated with tricuspid regurgitation was trisomy 21, but all types of karyotypic anomalies were seen in association. CONCLUSION: A careful search for tricuspid regurgitation is an important aspect of the evaluation of the early fetus, as this is frequently a marker for chromosomal defects even in the absence of structural heart disease.

Contractural arachnodactyly with mitral regurgitation and iridodonesis.

An infant girl with arachnodactyly, spontaneously resolving contractures, dolichostenomelia, iridodonesis, and mitral and tricuspid incompetence died in cardiac failure. We confirm that congenital contractural arachnodactyly may exhibit serious cardiovascular and ophthalmic complications like Marfan's syndrome. The presence of iridodonesis further obscures the differentiation between classical Marfan's syndrome and congenital contractural arachnodactyly.

Turner's syndrome in fetal life.

OBJECTIVE: To compare the incidence and type of heart disease found in association with 45X karyotype in fetal life with postnatal life and to examine the outcome after fetal diagnosis. METHODS: Fifty-three fetuses with a 45X karyotype were examined echocardiographically over a 4-year period between 1999 and 2002. Of these, 47 were referred because of increased nuchal translucency (NT). RESULTS: A cardiac abnormality was detected in 33/53 (62.2%) fetuses. The most common diagnosis was coarctation of the aorta in 24/53 (45.3%) fetuses, followed by the hypoplastic left heart syndrome (HLHS) in 7/53 (13.2%) fetuses. The mean NT was significantly higher in fetuses with a heart defect than in those with normal echocardiography. Termination of pregnancy was carried out in 45/53 (84.9%) fetuses and intrauterine death occurred in six cases. Two of four fetuses with a mosaic karyotype are currently alive. CONCLUSION: Turner's syndrome is associated with a higher incidence of heart defects detected prenatally when compared to postnatal reports. The commonest associated heart defects detected prenatally are HLHS and coarctation of the aorta, in contrast to postnatal life where a bicuspid aortic valve is the most common diagnosis. The typical intrauterine presentation of Turner's syndrome with a markedly increased NT or with hydrops and with a typical 45X karyotype has an extremely poor prognosis for intrauterine survival.

Acute pseudoaneurysm formation complicating balloon dilation of native coarctation: treatment by delayed surgical repair.

An 11-year-old boy developed an acute aortic pseudoaneurysm during balloon dilation of unoperated coarctation of the aorta. The pseudoaneurysm occurred despite the fact that the balloon catheter size did not exceed the diameter of the aorta at the diaphragm. Elective delayed surgical repair was successfully performed after 3 weeks of antihypertensive treatment when serial magnetic resonance imaging had demonstrated a reduction in the local tissue swelling.

Accuracy of central venous pressure measurements in the inferior vena cava in the ventilated child.

We compared central venous pressure measurements from three sites, superior vena cava, inferior vena cava and right atrium, in 12 children undergoing cardiac catheterization whilst on assisted ventilation. There was no significant difference between the mean pressures in the superior vena cava and the inferior vena cava. Furthermore, there was also no difference between the mean pressures in the inferior vena cava and the right atrium. Because of the greater safety of the placement of pressure monitoring lines in the inferior vena cava via the femoral vein, this approach should be the preferred route for central venous pressure monitoring in children.

Use of a second transcatheter Rashkind arterial duct occluder for persistent flow after implantation of the first device: indications and results.

OBJECTIVE: To assess the efficacy, feasibility, and most appropriate timing of the implantation of a second Rashkind arterial duct occluder because of persistent flow after the first device. DESIGN: A prospective serial Doppler study of patients after the insertion of a Rashkind arterial duct occluder including a subgroup in whom a second device was implanted. SETTING: A tertiary referral centre for congenital heart disease. PATIENTS: 144 patients aged 7 months to 67 years (median 3.38 years) who underwent transcatheter occlusion of patent arterial duct, 20 of whom had attempted implantation of a second device. INTERVENTIONS: Implantation of a second device alongside the first was attempted in 20 of the patients with persistent residual flow. MAIN OUTCOME MEASURES: Successful implantation of a second device, the incidence of complications, and the achievement of complete occlusion on follow up Doppler echocardiography. The time to complete occlusion in the whole group and factors predictive of persistent leak were also analysed. RESULTS: Second devices were successfully implanted in 19 of 20 first attempts and in the remaining patient at the second attempt. Complete occlusion was found in 19 patients at a mean follow up of eight months. The complications included fracture of a guidewire requiring femoral arteriotomy for its removal in one patient and embolisation of a device in another. With a single device, persistence of residual flow six months after implantation and malposition of the device on the aortogram after implantation were predictive of continuing residual patency. CONCLUSIONS: Implantation of a second device is safe, feasible, and effective and should be considered when residual flow persists beyond six months, or if malposition of the first device causes complications such as haemolysis.

Core-peripheral temperature gradient in children: does it reflect clinically important changes in circulatory haemodynamics?

Following open heart surgery, changes in core and peripheral skin temperature and changes in the core-peripheral temperature gradient were measured in 10 children. These were correlated with changes in cardiac index, systemic vascular resistance index, mean arterial pressure and urinary output. During the study intervals, which lasted 1 h each, no changes in medical management were made. Using Spearman's rank correlation, only a change in central venous pressure was found to correlate with a change in the core-peripheral temperature gradient. We conclude that a change in the core-peripheral temperature will give valuable information about the patient's intravascular volume.