Pulmonary atresia in prenatal life

Prenatally diagnosed case of tricuspid valve dysplasia: A case report with review of the literature

We present a case of fetal tricuspid valve dysplasia (TVD) and pulmonary atresia, diagnosed during a routine obstetric ultrasound scan. Serial fetal echocardiographic evaluations revealed progressively augmented prodigious thickening of the tricuspid valvular and subvalvular structures, which eventually extensively obliterated the right ventricle cavity. Thickened dysplastic valve displayed a "cotton-wool" appearance. Unusual configurations of three vessels in the three-vessel view were also observed on a consecutive gray scale and color Doppler scans. During pregnancy, the fetus exhibited satisfactory growth parameters, and complications of progressive hemodynamic compromise associated with TVD and pulmonary atresia such as grievous hydrops or arrhythmia did not develop till 39 weeks of gravidity.

Complex cardiac defect, bowing of lower limbs and multiple anomalies in trisomy 22. Ultrasound, post-mortem CT findings with necropsy confirmation

Trisomy 22 is commonly associated with severe intrauterine growth retardation and congenital anomalies. The sonographic identification of a complex cardiac defect and bowing of the long bones associated with multiple structural anomalies add new clinical informations to our knowledge about the prenatal phenotype of trisomy 22. These findings have not been reported previously and are of critical importance as sonographic signs of trisomy 22 may overlap that of trisomy 13-18 and will help clinicians in indicating fetal karyotyping. Prenatal diagnosis of trisomy 22 is essential as trisomy 22 is a lethal condition.

Significance of reverse orientation of the ductus arteriosus in neonates with pulmonary outflow tract obstruction for early intervention

Reverse orientation of the ductus arteriosus (RDA), defined as an inferior angle at the aortic junction of <90 degrees , is associated with pulmonary atresia; however, the significance of RDA in nonatretic pulmonary outflow tract obstruction (POTO) is unknown. The purpose of this study was to evaluate the relation between ductal morphology and the need for early intervention. Ductal morphology was retrospectively reviewed in 76 neonatal cases of POTO. Patients were stratified to those with conotruncal (CT) or primary pulmonary valve (PV) abnormalities. The prevalence of RDA was 40 of 68 (59%) and was higher in patients with CT defects (28 of 30, 93%) compared with PV abnormalities (12 of 38, 32%; chi-square = 26.4, p <0.0001). Early intervention was required in 29 of 40 patients with RDA (73%) compared with only 8 of 28 patients with normal ductal morphology (31%; chi-square = 12.8, p <0.001). The proportion of patients with RDA who required early intervention was greater in PV abnormalities (12 of 12, 100%) compared with CT defects (17 of 28, 61%; chi-square = 6.5, p <0.02). Importantly, after excluding patients with pulmonary atresia, these analyses were unchanged. In patients with nonatretic POTO, a threshold inferior angle of 65 degrees was predictive of the need for early intervention. RDA in patients with PV abnormalities, or CT defects and an inferior angle <65 degrees , is a specific indicator for early intervention. These findings demonstrate an association between RDA in the context of atretic and nonatretic POTO and the need for early intervention. The need for early intervention should be considered when RDA is identified in this population.

Current concepts in fetal cardiovascular disease

This article discusses the unique properties of the fetal cardiovascular system and patterns of blood flow in congenital heart disease. It also explores the complex interactive dependency between the developing heart and pulmonary vasculature, with particular attention to hypoplastic left heart syndrome. The article goes on to highlight some recent advances in the understanding of fetal cardiovascular medicine, specifically the possibilities and prognosis for fetal cardiac interventions. An understanding of the enigmatic process of twin-twin transfusion syndrome may help in elucidating one of the mechanisms for development of cardiac structural abnormalities in the fetus.

Fetal myocardial protection is markedly improved by reduced cardioplegic calcium content

BACKGROUND

Fetal cardiac surgery holds a clear therapeutic benefit in the treatment of lesions that increase in complexity due to pathologic blood flow patterns during development. Fetal and neonatal myocardial physiology differ substantially, particularly in the regulation of myocardial calcium concentration. To examine issues of calcium homeostasis and fetal myocardial protection, a novel isolated biventricular working fetal heart preparation was developed.

METHODS

Hearts from 20 fetal lambs, 115 to 125 days gestation, were harvested and perfused with standard Krebs-Henseleit (K-H) solution. The descending aorta was ligated distal to the ductal insertion and the branch pulmonary arteries were ligated to mimic fetal cardiovascular physiology. Hearts were arrested for 30 minutes with normocalcemic (n = 8), hypocalcemic (n = 6), or hypercalcemic (n = 6) cold crystalloid cardioplegia before reperfusion with K-H solution.

RESULTS

Compared with normocalcemic cardioplegia, hypocalcemic cardioplegia improved preservation of left ventricular (LV) systolic function (88% +/- 2.2% vs 64% +/- 15% recovery of end-systolic elastance, p = 0.02), diastolic function (12% +/- 21% vs 38% +/- 11% increase in end-diastolic stiffness, p = 0.04), and myocardial contractility (97% +/- 9.6% vs 75.2% +/- 13% recovery of preload recruitable stroke work [PRSW], p = 0.04). In contrast, the fetal myocardium was sensitive to hypercalcemic arrest with poor preservation of LV systolic function (37.5% +/- 8.4% recovery of elastance), diastolic function (86% +/- 21% increased stiffness), and overall contractility (32% +/- 13% recovery of PRSW). Myocardial water content was reduced in hearts arrested with hypocalcemic cardioplegia (79% +/- 1.8% vs 83.7% +/- 0.9%, p = 0.0006).

CONCLUSIONS

This study demonstrates the sensitivity of the fetal myocardium to cardioplegic calcium concentration. Hypocalcemic cardioplegia provides superior preservation of systolic, diastolic, and contractile function of the fetal myocardium.

Pulmonary stenosis and atresia with intact ventricular septum during prenatal life

AIM

To identify fetal echocardiographic characteristics predictive of perinatal outcome in cases with a prenatal diagnosis of pulmonary stenosis or pulmonary atresia.

PATIENTS AND METHODS

We retrospectively reviewed the records and the videotapes of all the cases of pulmonary stenosis and pulmonary atresia diagnosed at our institutions between 1990 and 1999. The following measurements were obtained: diameters of right and left atria and ventricles and ventricular wall thickness; main pulmonary artery and aortic root diameter; direction of flow through the atrioventricular, aortic and pulmonary valves and through the ductus arteriosus. Perinatal outcome and follow-up of the survivors were available in each case.

RESULTS

There were 21 cases of pulmonary atresia. Eleven were diagnosed before 24 weeks and nine of them (82%) underwent termination of pregnancy. The survival rate was 50% among the 12 fetuses born at term. None of the fetuses that survived had a large right ventricle, while this was a finding in 50% of those that died. Among the fetuses that died, 83% had a hypertrophic right ventricular wall compared to 33% of the survivors. There were 12 cases of pulmonary stenosis. Three cases were diagnosed before 24 weeks but none underwent termination of pregnancy. All the fetuses with pulmonary stenosis were born at term and four died in the perinatal period. The survival rate was thus 66.6% (8/12). Three (75%) of the fetuses that died had reversed flow in the ductus arteriosus compared with one of the fetuses that survived.

CONCLUSION

Our data suggest that a grossly enlarged right ventricle and/or a hypertrophied right ventricular wall in cases of pulmonary atresia and reversed flow in the arterial duct in cases of pulmonary stenosis are likely indicators of a poor prognosis.

Prenatal diagnosis of severe tricuspid insufficiency in Ebstein's anomaly with pulmonary atresia and intact ventricular septum: a case report

Pulmonary atresia with intact ventricular septum is an uncommon congenital cardiac anomaly which very often present varying degrees of downward displacement and dysplasia of the tricuspid valve. A 23-year-old woman was referred at 23 weeks' gestation because of fetal cardiomegaly detected by routine ultrasonography. Ebstein's anomaly with pulmonary atresia was diagnosed by fetal echocardiography. On pulsed Doppler examination, a severe tricuspid regurgitation was detected. Pulmonary atresia was suspected, as forward flow was not detected into pulmonary artery. The fetus was terminated at 25 weeks. At the postmorterm examination Ebstein's anomaly with pulmonary atresia and intact ventricular septum were confirmed. The finding of right atrial enlargement on an early sonogram should prompt the search for tricuspid valve abnormalities with tricuspid regurgitation and the presence or development of pulmonary atresia or stenosis. With the information provided, early detection of tricuspid valve disease should be possible so that the option of therapeutic abortion can be offered.

World experience of percutaneous ultrasound-guided balloon valvuloplasty in human fetuses with severe aortic valve obstruction

Prenatal alleviation of severe fetal aortic valve obstructions by percutaneous ultrasound-guided balloon valvuloplasty has been performed to improve the fate of affected fetuses. The purpose of this study was to analyze the current world experience of these procedures in human fetuses. Data from 12 human fetuses were available for analysis. The mean gestational age at intervention was 29.2 weeks (range 27 to 33). The mean time period between initial presentation and intervention was 3.3 weeks (range 3 days to 9 weeks). Technically successful balloon valvuloplasties were achieved in 7 fetuses, none of whom had an atretic valve. Only 1 of these fetuses remains alive today. Of the 5 remaining technical failures, 1 patient with severe aortic stenosis underwent successful postnatal intervention and remains alive. Six patients who survived prenatal intervention died from cardiac dysfunction or at surgery in the first days or weeks after delivery. Four fetuses died early within 24 hours after the procedure, 1 from a bleeding complication, 2 from persistent bradycardias, and 1 at valvotomy after emergency delivery. Thus, the early clinical experience of percutaneous ultrasound-guided fetal balloon valvuloplasty in human fetuses with severe aortic valve obstruction has been poor due to selection of severe cases, technical problems during the procedure, and high postnatal operative mortality in fetuses who survived gestation. Improved patient selection and technical modifications in interventional methods may hold promise to improve outcome in future cases.

Prenatal diagnosis of right ventricular outflow tract obstruction with intact ventricular septum, and detection of ventriculocoronary connections

OBJECTIVES

To determine the accuracy of prenatal diagnosis of pulmonary atresia and intact ventricular septum (PAIVS), and pulmonary stenosis, including prenatal detection of ventriculocoronary connections, to evaluate heart size during the prenatal period, and to evaluate the outcome.

DESIGN AND PATIENTS

Medical records of 20 cases with prenatally diagnosed PAIVS and pulmonary stenosis were reviewed retrospectively. Prenatal and postnatal echocardiography were also reviewed and dimensions of the ventricles and vessels were measured retrespectively.

RESULTS

Of 20 prenatal diagnoses (15 PAIVS and five pulmonary stenosis), 16 were confirmed as correct. One critical pulmonary stenosis case had been diagnosed as PAIVS prenatally; three had no confirmation. Eight pregnancies were terminated, three had no active treatment, and nine were treated; all survived. Of 13 assessed with ventriculocoronary connections prenatally, seven were diagnosed correctly (four with, three without ventriculocoronary connections), but one was falsely positive; five had no confirmation. The more prominent hypoplasia of the main pulmonary artery and the tricuspid valve annulus, and the sigmoid shape of the ductus arteriosus, seemed to be associated with the presence of ventriculocoronary connections.

CONCLUSIONS

Current prenatal echocardiography can accurately diagnose right ventricular outflow tract obstruction and ventriculocoronary connections. Prenatal detection of this constellation of abnormalities aids in family counselling and decisions on postnatal management.

Evaluation and management of pulmonary atresia with intact ventricular septum

Pulmonary atresia with intact ventricular septum (PA/IVS) is a spectrum of diseases with varying severity of right ventricle hypoplasia and potential for biventricular, univentricular, or hybrid repairs. Pessimistic outcome measures for PA/IVS may give way to optimism with the refinement of early diagnosis and early intervention to encourage right ventricle flow and optimize growth. To this end, PA/IVS has become a focus of innovative interventions (e.g., fetal surgery) and new catheter-based and surgical techniques.

Factors affecting the prognosis of Ebstein's anomaly during fetal life

BACKGROUND

The echocardiographic criteria that have been used to evaluate severity of Ebstein's anomaly in utero are the same as those applied after birth.

OBJECTIVE

The objective of this study was to establish prognostic criteria that take into account the peculiarities of the fetal hemodynamics.

METHOD

The video recordings of eight fetuses with Ebstein's anomaly were retrospectively reviewed.

RESULTS

The following indexes had no prognostic significance either on fetal or neonatal outcome: the ratio of functional tricuspid opening over the diameter of the annulus, the degree of displacement of the tricuspid valve opening, and the degree of tricuspid regurgitation. The index of severity (based on the surfaces of right atrium + atrialized right ventricle) and the cardiothoracic ratio had a significant impact only on neonatal survival. The smallest fossa ovalis were found in two fetuses who had hydrops. Fetuses who reached term without problems had higher left ventricular outputs. A positive linear correlation was found between the z score of the left ventricular output and the size of the fossa ovalis (r = 0.81, p < 0.05).

CONCLUSION

The prognosis of Ebstein's anomaly during fetal life is not influenced by criteria described for postnatal life and may be related to factors that control the volume load of the left ventricle.

Prenatal diagnosis of pulmonary atresia by fetal echocardiography

With an improvement in cardiac imaging during the past 20 years, fetal echocardiography has progressively altered the practice of obstetricians and become a principle armamentarium for the diagnosis of fetal heart diseases. We presented a case of pulmonary atresia with intact ventricular septum diagnosed prenatally using fetal echocardiography.

Fetal echocardiography

Fetal echocardiography has provided a means for the detailed assessment of cardiac structure and function from early prenatal life. Indications for a fetal echocardiographic examination and the potential implications for individuals caring for newborns with cardiac malformations are discussed.

Capillary distribution in the ventricles of hearts with pulmonary atresia and intact ventricular septum

BACKGROUND

Pulmonary atresia and intact ventricular septum (PA-IVS) can be complicated by the presence of a severely hypoplastic thick-walled right ventricle with or without ventriculo-coronary arterial communications. A variable amount of myocardial pathology has been described in these hearts, probably the result of ischemic conditions and a high pressure in the right ventricle. We studied whether the capillary network is still intact, allowing a sufficient perfusion of the myocardium, which will be important for the success of palliative surgery.

METHODS AND RESULTS

We studied the distribution of capillaries in the myocardium of hearts with PA-IVS and compared the results with normal hearts. The capillaries were detected by immunohistochemistry using a monoclonal antibody (408) against endothelium. Remarkable abnormalities in capillary distribution were found in the right ventricle of hearts with PA-IVS and reflect the arrangement of the myocytes. Thus, disorganization of capillaries, which is found to be the most common pattern, always paralleled the myocardial disarray. A low density of capillaries is always found in areas with a low density of myocytes, ie, with hypertrophied myocytes, compact fibrotic tissue, or diffuse fibrosis. Disarray and other disturbances in orientation of capillaries and myocytes are present in hearts with PA-IVS, a hypoplastic right ventricle, and ventriculo-coronary arterial communications. These disturbances are more extensive when interruptions of the coronary arteries are also present. In hearts with PA-IVS and a hypoplastic right ventricle only, extensive regions with low capillary densities and severe myocyte pathology are observed. On the contrary, hearts with PA-IVS and a normal-size right ventricle show minor abnormalities in capillary and myocyte organization.

CONCLUSIONS

In hearts with PA-IVS, various abnormal capillary distribution patterns are found. Our findings correlate well with clinical data that reported the best surgical results in hearts in which the major part of the myocardium showed a normal capillary distribution and myocyte morphology. This suggests that the capillary distribution may be an important parameter for the function of the heart. Because the distribution of the capillaries is found to be a good reflection of the arrangement of the myocytes, antibody 408 is also a useful tool in detecting abnormalities of the myocardium in a fast and easy way.

The prevalence and clinical significance of fetal tricuspid valve regurgitation with normal heart anatomy

OBJECTIVE

Our purpose was to assess the prevalence, cause, and clinical significance of fetal tricuspid valve regurgitation in structurally normal hearts during indicated fetal echocardiographic examination.

STUDY DESIGN

The prevalence of fetal tricuspid regurgitation was retrospectively evaluated in a group of 733 singleton fetuses referred for routine fetal echocardiography.

RESULTS

The prevalence of this abnormality was 6.8%. Tricuspid valve regurgitation was most frequent in the group referred for fetal echocardiography to evaluate indomethacin exposure, followed by maternal diabetes. Factors associated with tricuspid valve regurgitation included ductal constriction, abnormal heart rhythm, atrial septal aneurysm, congestive heart failure, pericardial effusion, myocardial hypertrophy, and extracardiac malformations. Fetal tricuspid valve regurgitation was trivial in 80% (nonholosystolic, maximum velocity < 2 m/sec) and was significant in 20% (holosystolic, maximum velocity > 2 m/sec). Neonatal follow-up of tricuspid valve regurgitation was unremarkable.

CONCLUSIONS

Fetal tricuspid valve regurgitation with normal heart anatomy was a frequent finding during indicated fetal echocardiographic examination and may indicate abnormal physiologic characteristics (increased preload or afterload, myocardial impairment, or arrhythmia). In the majority of cases (92%) the possible cause may be established. In other cases (8%) there may be "idiopathic" tricuspid valve regurgitation.

Sonographic differential diagnosis of fetal cardiac abnormalities

Ultrasonographic evaluation of the fetal heart for structural and functional abnormalities is vital for prenatal diagnosis and perinatal management. Even more important than up-to-date diagnostic equipment is keen observation and an understanding of fetal cardiac abnormalities. One diagnostic approach begins with the four-chamber view with particular attention to the normal symmetric sizes of all four cardiac chambers. Ventricular disproportion, inequality in ventricular size, is often an easily detectable sign of a cardiovascular abnormality. Segmental diagnosis of cardiac and visceral situs, ventricular outflow tracts for conotruncal abnormalities and the aortic and ductal arches is also vital for diagnosing affected fetuses.

Correlation between echocardiographic and morphological investigations of lesions of the tricuspid valve diagnosed during fetal life

OBJECTIVE

To assess the degree of agreement between the fetal echocardiographic and postmortem examination of hearts from fetuses with severe malformations of the tricuspid valve.

DESIGN

A retrospective study to analyse echocardiographic recordings and make comparisons with postmortem findings.

SETTING

Tertiary referral centre for fetal echocardiography. Institute for cardiac morphology.

PATIENTS

19 cases shown to have severe malformation of the tricuspid valve by fetal echocardiography that died in the prenatal or neonatal period.

MAIN OUTCOME MEASURES

Correlations between morphology and measurements made at echocardiography and necropsy.

RESULTS

The echocardiographic diagnosis was Ebstein's malformation in seven and tricuspid valvar dysplasia in 12 fetuses. These findings were confirmed in six and eight cases at necropsy. In one false positive diagnosis of Ebstein's malformation, necropsy showed dysplasia of the leaflets of the tricuspid valve without displacement. In four cases with the echocardiographic diagnosis of valvar dysplasia, necropsy showed displacement, the hallmark of Ebstein's malformation. Associated malformations that are known to worsen prognosis were predicted correctly by echocardiography. Taking the mean duration of four weeks between echocardiographic and postmortem investigations, both methods showed cardiomegaly causing lung hypoplasia, right atrial dilatation, and relative hypoplasia of the pulmonary trunk, morphometric factors that may be responsible for the poor outcome. Mostly good agreement existed between the echocardiographic and postmortem measurements if cases with an interval of more than eight weeks between the measurements were excluded.

CONCLUSION

Fetal echocardiography was proved to be a reliable technique in differentiating the variants of tricuspid valvar disease, in diagnosing associated cardiac lesions, and in predicting quantitative factors that can define the subsequent outcome.

Role of prenatal echocardiography in the study of hypertrophic cardiomyopathy in the fetus

The increased incidence of hypertrophic cardiomyopathy in children of diabetic mothers has already been demonstrated, but its prenatal diagnosis has not yet been extensively studied. The purpose of this prospective study was to evaluate the frequency, severity, and echocardiographic features of fetal hypertrophic cardiomyopathy in a population with several indications for prenatal echocardiography. From March 1987 to April 1991, 283 fetuses were submitted to comprehensive prenatal echocardiography, including M-mode measurements, cross-sectional imaging, Doppler studies, and color flow mapping. One hundred seventy-six were pregnancies complicated by previous or gestational diabetes. The diagnosis of disproportionate septal hypertrophy was made in 39 fetuses (mean septal thickness 7.12 +/- 1.6 mm), at a mean gestational age of 32 weeks. Diabetes mellitus was present in 36 of these pregnancies (92.3%). In four cases, nonimmune hydrops was detected. A systolic anterior motion of the mitral valve was present in three fetuses, but only one showed a gradient across the left ventricular outflow tract. Postnatal echocardiographic examination in 27 babies did not show false positivity. In ten cases, spontaneous regression of the septal hypertrophy was shown. There were three neonatal deaths, unrelated to the myocardial disease. We concluded that transient hypertrophic cardiomyopathy is a frequent entity, especially when associated with diabetes during gestation, being a potential cause for nonimmune hydrops. Fetal echocardiography is the method of choice for its prenatal diagnosis and should always be indicated in diabetic mothers.

Tricuspid valve dysplasia or displacement in intrauterine life

In 450 cases of structural heart disease diagnosed prenatally, 38 fetuses (8.5%) had either a dysplastic or a displaced tricuspid valve. The tricuspid valve was dysplastic in 22 fetuses, all of which had evidence of tricuspid regurgitation resulting in right atrial dilation and increased cardiothoracic ratio. An associated abnormality of the pulmonary valve occurred in 16 fetuses. The remaining 16 fetuses had Ebstein's malformation, 14 with evidence of tricuspid incompetence at presentation and 10 with an associated abnormality of the pulmonary valve. Of the 38 cases, the pregnancy was interrupted in 17, spontaneous intrauterine fetal death occurred in 8, 11 infants died postnatally and 2 infants are still alive; additional abnormalities were found in 8 cases (chromosomal anomalies in 2, ventricular septal defects in 2, corrected transposition in 2, the Chiari malformation in 2, supraventricular tachycardia in 1 case and coarctation of the aorta in 1). Fetuses with severe abnormalities are selected for fetal echocardiography by the four chamber screening program and a high rate of natural loss both in intrauterine life and immediately after birth was observed in the 21 cases in which pregnancy was continued. This would explain the higher incidence of tricuspid valve disease in our prenatal compared with postnatal series. Although increased cardiothoracic ratio and associated lesions of the right ventricular outflow tract contribute to the poor outcome in the cases detected prenatally, the absence of these features does not always indicate a good prognosis because progression of disease can occur with advancing gestational age. No absolute measurement or single echocardiographic feature emerged as a consistent predictive factor of prognosis.

Fetal echocardiography

Examination of the fetus offers a unique opportunity to understand the true scope of congenital and early acquired cardiac lesions. Diagnosis and management of arrhythmias remain the predominant use of these techniques. Structural heart disease can be completely characterized by two-dimensional and Doppler examination. Such studies enhance our understanding of heart disease and also provide the family and patient care team with valuable information for the planning of neonatal management. These advances in technology and emphasis on increased fetal salvage are expected to usher in the next age of surgical intervention in the fetus with structural heart disease. The ability to examine the fetus at increasingly earlier stages of gestation will provide invaluable means for unraveling the secrets of the origins of many cardiovascular alternations.

Tricuspid valve disease with significant tricuspid insufficiency in the fetus: diagnosis and outcome

The echocardiographic studies and clinical course of 27 fetuses (mean gestational age 26.9 weeks) diagnosed in utero with tricuspid valve disease and significant tricuspid regurgitation were reviewed. The diagnosis of Ebstein's anomaly was made in 17 of the fetuses, 7 had tricuspid valve dysplasia with poorly developed but normally attached leaflets and 2 had an unguarded tricuspid valve orifice with little or no identifiable tricuspid tissue. One fetus was excluded from data analysis because a more complex heart lesion was documented at autopsy. All fetuses had massive right atrial dilation and most who were serially studied had progressive right-sided cardiomegaly. Hydrops fetalis was found in six cases and atrial flutter in five. Associated cardiac lesions included pulmonary stenosis in five cases and pulmonary atresia in six. Four fetuses with normal forward pulmonary artery flow at the initial examination were found at subsequent study to have retrograde pulmonary artery and ductal flow in association with the development of pulmonary stenosis (n = 1) and pulmonary atresia (n = 3). On review of the clinical course of the 23 fetuses (excluding 3 with elective abortion), 48% of the fetuses died in utero and 35% who were liveborn died despite vigorous medical and, when necessary, surgical management, many of whom had severe congestive heart failure. Of the four infants who survived the neonatal period, three had a benign neonatal course, all of whom were diagnosed with mild to moderate Ebstein's anomaly; only one had pulmonary outflow obstruction. An additional finding at autopsy was significant lung hypoplasia documented in 10 of 19 autopsy reports.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of colour Doppler in fetal echocardiography

Doppler colour flow mapping provides a non-invasive method for studying patterns of blood flow in the cardiovascular system. We undertook a prospective study using this technique in order to document normal and abnormal patterns in the human fetus. A group of 50 consecutive normal fetuses were examined with colour flow mapping. Patterns of flow that could be readily identified in the majority included inflow at the atrioventricular valves, outflow through the arterial valves and flow in the aortic arch and arterial duct. Flow across the oval foramen and in the pulmonary veins was identified in approximately half the patients. Colour Doppler also proved helpful in the detection and definition of cardiac anomalies. A series of 74 cardiac malformations, seen during 1988, were examined with colour flow mapping. The presence or absence of flow across valves could be confirmed, valvar incompetence demonstrated and the direction of blood flow displayed across both normal and abnormal communications. Colour Doppler studies in the human fetus can thus improve the understanding of the characteristics of flow of blood and add to the accuracy of antenatal diagnosis of congenital heart disease.

Congenitally unguarded tricuspid orifice: its differentiation from Ebstein's malformation in association with pulmonary atresia and intact ventricular septum

Dysplasia of the leaflets is a well-known integral part of Ebstein's malformation. It is less well-recognized that occasionally the septal leaflet may be completely absent and not simply displaced from its usual annular attachment. This may make it difficult to differentiate by echocardiography between Ebstein's malformation and the rare lesion in which the tricuspid orifice is completely devoid of leaflet tissue ("congenitally unguarded orifice"). A neonatal case is described in which a partially unguarded orifice was present in association with pulmonary atresia and intact ventricular septum but misdiagnosed as Ebstein's malformation. In addition we reviewed the morphologic features of all 46 cases of pulmonary atresia and intact septum in the Cardiopathological Collection of the Children's Hospital of Pittsburgh: 17 also had Ebstein's malformation, while three had a congenitally unguarded tricuspid orifice. We found that the differential diagnosis occurred when the right ventricle was dilated rather than being a hypoplastic cavity, as was a feature of all the cases with unguarded orifice and five of those with Ebstein's malformation. The difference between the lesions is best demonstrated by examining the mural leaflet of the valve, which is absent when the orifice is unguarded but displaced in association with Ebstein's malformation. This feature should be recognizable by cross-sectional echocardiography. We have confirmed previous studies that dilatation of the chambers of the right heart indicates a very poor prognosis in cases with pulmonary atresia and an intact ventricular septum.

Fetal echocardiographic diagnosis of congenital heart disease

The delineation of the structural and functional abnormalities of the fetal heart by echocardiography has led to the emergence of a new and vital subspecialty, that of fetal cardiology. Its practitioners are from disciplines such as genetics, obstetrics, and pediatrics, the common interests of which in the well-being of the unborn child have converged as technologic advances in ultrasound have enabled detailed evaluation and sometimes treatment of fetal hemodynamic abnormalities. Each discipline forms an entry point for the identification and referral of the high-risk patient or fetus with a suspected abnormality. As has been shown obstetric cardiac screening of the general population with ultrasound provides the highest yield of cardiac malformations when suspicious findings are referred to a subspecialist in fetal cardiac sonography. As we study the pathogenesis of congenital defects, it is likely that hitherto unidentified high risk populations will be found. The future holds the possibility of meaningful surgical interventions that may change the dismal outcome of fetuses with certain, now lethal cardiac malformations. Patients with hydrops fetalis due to congenital complete heart block are almost certain to die. Intrauterine cardiac pacing has been attempted and is a potentially life-saving procedure. Patients in whom pulmonary underdevelopment occurs because of the cardiac enlargement associated with some types of pulmonary atresia could potentially benefit from intrauterine surgery such as valvotomy. Serial fetal echocardiographic examination of the developing heart with higher resolution equipment during the first trimester may one day pinpoint the exact moment of teratogenesis and lead to more specific treatments designed to restore normal embryogenesis. Such examinations will, when known to be safe themselves, at the very least significantly advance our knowledge of normal cardiac embryogenesis and pathogenesis.

Congenital pulmonary atresia with intact ventricular septum, tricuspid insufficiency, and patent ductus arteriosus in two sibs

Pulmonary atresia comprises only 1% of all congenital heart defects. Counseling the parents on recurrence risks is difficult. We present a rare case of pulmonary atresia in two sibs, along with a review of the literature.

Pulmonary stenosis with intact ventricular septum: documentation of development of the lesion echocardiographically during fetal life

We describe a case of severe pulmonary stenosis with intact interventricular septum diagnosed during fetal life at 34 weeks gestational age. An echocardiographic examination had been performed on the same fetus at 20 weeks, when no cardiac anomalies were observed. It is concluded that this form of pulmonary stenosis might be a lesion either acquired during fetal life or becoming progressively more severe in the prenatal period.