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(Circulation. 2004;110:1743-1746.)
© 2004 American Heart Association, Inc.
Congenital Heart Disease |
From Maternité (J.-M.J., L.G., S.P., Y.D.) and Service de Cardiologie Pédiatrique (J.L.B., P.R.V., D.S., D.B.), Hôpital Necker-Enfants Malades, and the Institut de Puériculture (L.F.), Paris, France.
Correspondence to Damien Bonnet, Cardiologie Pédiatrique, Hôpital Necker Enfants Malades AP-HP, 149, rue de Sèvres 75743 Paris cedex 15, France, EU. E-mail damien.bonnet{at}nck.ap-hop-paris.fr
Received April 4, 2003; de novo received April 7, 2004; revision received May 17, 2004; accepted May 18, 2004.
| Abstract |
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Methods and Results The outcomes of 130 fetuses with TGA were reviewed over a period of 5.5 years. Restriction of the FO and/or constriction of the DA could be analyzed in 119/130 fetuses at 36±2.7 weeks of gestation. Twenty-four out of 119 had at least 1 abnormal shunt (23 FO, 5 DA, and 4 both). Thirteen of 130 neonates had profound hypoxemia (PaO2<25 mm Hg) and metabolic acidosis (pH <7.15) in the first 30 minutes and required immediate balloon atrioseptostomy. Two who had abnormal FO and DA died despite aggressive resuscitation. The specificity and sensitivity of the fetal echo in predicting neonatal emergency were 84% and 54%, respectively. The specificity and sensitivity of a combination of restrictive FO and DA constriction were 100% and 31%, respectively.
Conclusions Restriction of the FO and/or of the DA has a high specificity to predict the need for emergency neonatal care in fetuses with TGA, but the sensitivity is too low to detect all high-risk fetuses. Exceptional procedures should be considered for fetuses that have a combination of restrictive FO and DA constriction.
Key Words: heart defects, congenital transposition of great vessels echocardiography
| Introduction |
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| Methods |
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Echocardiographic Examinations and Measurements
The fetal echocardiographic examinations were performed with various probes on an Acuson 128XP (1997 to 1999) or Acuson Sequoia (1999 to 2003) (Acuson). All images were recorded on videotape for off-line analysis. Prenatal features of the foramen ovale and of the ductus arteriosus were reviewed retrospectively for the period November 1997 and November 1999 and described prospectively during the second period of the study. According to Maeno et al9 and Wilson et al,14 the foramen ovale was considered at risk of postnatal early restriction if the aneurysmal septum primum bulged >50% of the way across to the left atrial free wall; if the angle between the septum primum and the rest of the atrial septum was <30°; or if the septum did not have the typical swinging motion during the cardiac cycle. For the ductus arteriosus, the diameter was measured at the narrowest portion, typically at the pulmonary end. The Doppler flow pattern was considered abnormal if it was either antegrade and continuous or bidirectional.
Immediate Neonatal Management
All fetuses were delivered in our institution. For each patient, a senior pediatric cardiologist and a senior pediatric intensivist were in charge of immediate evaluation and management. Echocardiography and catheterization equipment were available in the maternity ward, as was prostaglandin E1. The catheterization laboratory was left free before delivery to allow early balloon atrioseptostomy (BAS).
Clinical status at birth was evaluated by Apgar score, transcutaneous oxygen saturation at 10 minutes, need for mechanical ventilation, and acidosis (pH <7.15). The physicians in charge of the patient made the decision to perform BAS, regardless of the prenatal findings. It was based on the infant clinical condition and neonatal restriction of the foramen ovale.
Neonates were considered to be in "critical condition" at birth if they had a PaO2 level <25 mm Hg and a pH <7.15. All patients in this group underwent BAS within the first 30 minutes after delivery. Patients were considered to be in "stable condition" if they did not fulfill the above criteria. In this group, BAS was performed any time after delivery according to the decision of the pediatric cardiologist.
Prostaglandin E1 infusion was started when mixing was considered insufficient in patients with isolated TGA or TGA with ventricular septal defect, and in all patients with TGA and coarctation of the aorta. The arterial switch was performed in our institution in the majority of the patients (n =119) by one single surgeon (P.R.V.); the remaining 11 patients were operated on in 2 other surgical units.
Statistical Analysis
Summary statistics are presented as mean±SD and range. Percentages are presented as %±95% confidence interval (CI). Comparisons of data were made by unpaired Students t test or the Mann-Whitney test as appropriate for interval variables.
2 analysis or Fishers exact test was used for categorical variables. Statistical significance was assessed by use of a cutoff value of P=0.05.
| Results |
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Prenatal Findings at Late Echocardiographic Control
One hundred nineteen late fetal echos performed at 36±2.7 weeks of gestation were available for review (Table 1). The 11 cases that could not be adequately reviewed included 6 cases of isolated TGA and 5 cases of TGA with ventricular septal defect.
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An abnormal prenatal feature of the foramen ovale and/or the ductus arteriosus at 34 to 38 weeks was noted in 24/119 cases (20.2%, 95% CI, 12.8 to 27.5%). Twenty-three of 119 fetuses (19.3%; mean gestational age 36±3 weeks gestation) had an abnormal appearance of the foramen ovale. The ductus arteriosus appearance could be assessed in 22/23 of them. In 5/104 fetuses (4.8%), the ductus arteriosus appeared constricted at the pulmonary artery end (diameter <3 mm; mean gestational age, 35±3 weeks gestation). Four of these 5 had a continuous accelerated pulmonary artery-to-aorta flow through the ductus arteriosus with associated restrictive foramen ovale. The remaining fetus had a constricted ductus arteriosus with a bidirectional turbulent flow without abnormal appearance of the foramen ovale. Finally, 95/119 fetuses had normal prenatal features of the foramen ovale and of the ductus arteriosus.
Relation Between Prenatal Findings of Risk of Early Demise and Neonatal Management and Outcome
In the group of 24 patients with either potential restriction foramen ovale and/or the ductus arteriosus, 7/24 were in critical condition. In the 95 neonates in whom prenatal shunts were considered normal at last fetal echo, only 6/95 were in critical condition (P<0.01). None of the 11 neonates whose late fetal echo was not available were in critical condition. The specificity of these features to indicate neonatal critical condition was 84%, but the sensitivity was low (54%). The positive predictive value was 29% and the negative predictive value was 94%.
The 5 patients who had a restrictive ductus arteriosus were in critical condition at birth. The 2 neonatal deaths that occurred before surgery were observed in patients with both abnormal physiological shunts at 36 weeks gestation. For the first patient, Apgar scores were 3 and 1 at 1 and 5 minutes, respectively. Immediately after birth, the child exhibited general profound cyanosis associated with bradycardia (50 bpm). Blood gas analysis at 18 minutes of life showed major acidosis (pH=6.8, base excess=16 mmol/L). Despite resuscitation, BAS, and prostaglandin E1 infusion, she died after 3 days with severe cerebral damages. In the second case, the hemodynamic condition rapidly deteriorated after birth. The first attempt of BAS failed to achieve a sufficient atrial septotomy, and the hemodynamic conditions worsened despite intravenous infusion of prostaglandin E1 and mechanical ventilation. A second attempt for BAS performed at 4 hours of life successfully achieved significant interatrial mixing. This child died at 3 days of life after neurological deterioration with iterative convulsions. The specificity of 2 abnormal shunts in predicting neonatal emergency was 100%, but the sensitivity remained at 31%. The positive predictive value of 2 abnormal prenatal shunts for critical condition was 100%, and the negative predictive value was 92%.
In the 128 neonates who survived, we did not observe any severe acidosis, multiorgan failure, or neurological complications during the preoperative period.
| Discussion |
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In this series, only 10% of the patients required urgent management. This percentage is higher than the reported preoperative mortality of 4%. As the facilities of our institution allowed us to perform a BAS in an emergency, it is possible that some of these patients could have been stabilized over a few hours with prostaglandin E1 infusion, mechanical ventilation, and volume expansion. However, 2 patients of the present series died immediately after birth despite aggressive resuscitation, confirming that there is a subset of patients with TGA and intact ventricular septum with tenuous intercirculatory mixing in utero. These 2 patients had a restrictive foramen ovale and a constricted ductus arteriosus. In addition, the 2 other patients who exhibited the same prenatal echo features required immediate aggressive management. This suggests that this subgroup of patients may be helped only by immediate BAS before discontinuation of the placental circulation or immediate cannulation for mechanical cardiopulmonary support.17 Indeed, the positive predictive value of at least 1 abnormal prenatal shunt was 30%, but it became 100% if we considered only the fetuses who had restrictive foramen ovale and constricted ductus arteriosus. We are aware that most institutions cannot easily create a delivery suite for all prenatally diagnosed infants, but our results show that in this particular situation, exceptional delivery procedure and neonatal management should be considered.
Fetal appearance of the physiological shunts is helpful in predicting which infants will indeed require emergent intervention, but its sensitivity is not sufficient to detect all fetuses at risk. This low sensitivity might be explained by the limitations of our study. Fortunately, none of the 11 neonates who could not be fully reviewed prenatally were in critical condition. The last fetal echocardiography was performed at 36±2.7 weeks of gestation and the appearance of the shunts could have changed during the last weeks of gestation. To improve the sensitivity of these abnormal features, we will attempt to examine the foramen ovale and the ductus arteriosus the day before delivery, as we have a policy of planned delivery. Finally, the fetal echocardiographic criteria that we used for neonatal restriction of the foramen ovale or the ductus arteriosus might not be sufficiently stringent. Sequential measures of the size of the foramen ovale during the third trimester are currently performed in our new cases of fetal TGA to attempt to increase sensitivity.
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| Acknowledgments |
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| References |
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ur. 1997; 90: 667672.This article has been cited by other articles:
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F. Kaguelidou, L. Fermont, Y. Boudjemline, J. Le Bidois, A. Batisse, and D. Bonnet Foetal echocardiographic assessment of tetralogy of Fallot and post-natal outcome Eur. Heart J., June 1, 2008; 29(11): 1432 - 1438. [Abstract] [Full Text] [PDF] |
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