Surgical therapy for tetralogy of fallot is one of the success stories of the early era of cardiac surgery. Despite the many advances of the ensuing fifty years, such as new techniques for imaging, extension of surgical therapy to the neonatal period, and improved treatment in the intensive care unit, there has been an increasing recognition that the outcomes for many patients over the long term remain less than optimal. Mortality for surgical correction of tetralogy of Fallot, even in very small neonates, approaches zero at most institutions. Patients remain at risk, however, for right ventricular dysfunction, congestive heart failure, and an ongoing need for future therapeutic interventions, including cardiac catheterization and re-operation. Surgical reconstruction of the abnormal subpulmonary right ventricular outflow tract often results in pulmonary insufficiency and scarring, leading to ventricular volume overload and dysfunction. Postoperative right ventricular dysfunction may be associated with congestive heart failure, poor exercise tolerance, arrhythmias, and sudden death. The chapters which follow in this section of our supplement focus on the current state of knowledge concerning treatment and management of patients with pulmonary insufficiency following surgical repair of tetralogy of Fallot. There is considerable controversy concerning the clinical significance of pulmonary insufficiency; there is no standard technique for the assessment of right ventricular function; and there are considerable disagreements concerning the optimal timing of surgical re-intervention to replace the pulmonary valve. I believe that the reviews will help clarify these important issues.

It is now well over one hundred years since Arthur Louis Etienne Fallot showed that four discrete morphologic abnormalities co-existed in the majority of patients he had autopsied with “la maladie bleu”,1 or cyanosis as we now describe it. The lesions he identified were an interventricular communication, subpulmonary stenosis, biventricular origin of the aortic valve, and right ventricular hypertrophy. We now know that the combination of these anomalies had been recognised long before Fallot's epochal description. Indeed, it is Neils Stensen, the Danish monk who also described the parotid duct, who is usually acknowledged as being the first to describe the entity that we now call tetralogy of Fallot.2 Cases were certainly described by John Hunter,2 whilst with the benefit of hindsight, we can see an unequivocal example illustrated by the Baron von Rokitansky3 in his ground-breaking atlas (Fig. 1).

Some patients with pulmonary atresia with an intact ventricular septum, mild to moderate right ventricular hypoplasia, and a patent infundibulum remain duct dependent on the flow of blood through the arterial duct despite adequate relief of the obstruction within the right ventricular outflow tract.

The objective of our study was to review the risk factors for stenting of the patent arterial duct, or construction of a Blalock-Taussig shunt, in the patients with pulmonary atresia and an intact ventricular septum who remain duct-dependent following radiofrequency valvotomy and dilation of the imperforate pulmonary valve.

We reviewed the data from 53 patients seen between November 1995 and December 2001. Of the 47 patients who survived, 6 required stenting of the patent arterial duct, while 4 needed construction of a modified Blalock-Taussig shunt to augment the flow of blood to the lungs at a mean of 7 plus or minus 5.7 days following the initial intervention. The remaining 37 patients required no additional procedures. We compared the findings in these two groups.

The mean diameter of the tricuspid valve in the patients requiring early reintervention was 8.5 plus or minus 3.7 millimetres, giving a Z-score of −1.1 plus or minus 1.47, whilst those in the group without early reintervention had values of 10.7 plus or minus 2.2 millimetres, giving a Z-score of −0.58 plus or minus 1.18 (p equal to 0.003). No statistically significant differences were found in right ventricular morphology, McGoon ratio, or residual obstruction across the right ventricular outflow tract after decompression of the right ventricle.

The diameter of the tricuspid valve, therefore, appears to be the only factor predicting the need for augmentation of flow of blood to the lungs. As just over one-fifth of our survivors required such augmentation, we hypothesize that stenting of the patent arterial duct may be performed as an integral part of primary transcatheter therapy in patients with pulmonary atresia and intact ventricular septum who have moderate right ventricular hypoplasia and a small tricuspid valve.

Aims: The purpose of our study was to ascertain the outcome of the construction of a Blalock–Taussig shunt in patients aged 12 years and over. Patients and methods: We identified 21 patients in whom a Blalock–Taussig shunt had been constructed subsequent to the age of 12 years. Of the patients, 9 were female, and their median age was 18.5 years, with a range from 12 to 46 years. All had usual atrial arrangement, and the atrioventricular connections were concordant in 11, with univentricular atrioventricular connection in 10. Pulmonary atresia was present in 8 (38 per cent), and pulmonary stenosis, either valvar or subvalvar, in 13. An interposition graft had been placed between the subclavian and pulmonary arteries in 16 patients, and an end-to-side anastomosis between the arteries in 5. Results: One patient had died in hospital, while 4 patients had died during the period of follow-up after initial construction of the shunt. Long-term follow-up was available in 86 per cent of patients. In the 3 patients lost to follow-up, the shunt had been known to be functioning at periods of 4, 8, and 10 years, respectively. Actuarial freedom from death after a period of 17 years was 76 per cent. In 8 patients, a period of 10 years had elapsed with the shunt patent, and a further 10 had a patent shunt after 5 years follow-up. Symptomatic improvement was reported in 16 (76 per cent) patients, although adverse cardiac events had occurred during follow-up in 17, including congestive heart failure in 3, atrial fibrillation in 3, and endocarditis in 2. In 2 patients, it had been possible to proceed to biventricular repair, one with tetralogy of Fallot, and the other having a Rastelli procedure. Further in 3 patients, it had been possible to construct the Fontan circulation, or one of its variants. One patient has undergone cardiac transplantation, while 2 are awaiting transplantation. Conclusions: Symptomatic improvement can be achieved by construction of a Blalock–Taussig shunt in older subjects, and the risks of surgery are low. Later repair may be feasible in some patients, but adverse cardiac events may follow the increased volume load on the systemic ventricle.

Introduction: Postoperative thrombosis after a cavopulmonary connection has been widely described. Abnormalities in coagulation seem to occur early in the course of patients with functionally univentricular physiology, and may precede surgery. Endothelial abnormalities due to chronic hypoxia, and hyperviscosity, may contribute to this scene. The purpose of our study was to investigate if patients with a superior cavopulmonary connection have altered levels of endothelial and coagulative markers in the plasma. Methods: We compared findings in 10 patients, aged from 4 to 19 years, with 6 age-matched normal controls. We measured levels of von Willebrand factor antigen, thrombomodulin, tissue-type plasminogen activator, plasminogen activator inhibitor-1 and d-dimer in the plasma using enzyme-linked immunosorbent assay. Results: We found increased levels of von Willebrand factor antigen (p = 0.01), tissue-type plasminogen activator (p = 0.01), and decreased levels of thrombomodulin (p = 0.008) in the patients when compared to controls, while levels of plasminogen activator inhibitor-1 were not different. Values of d-dimer were within the reference range. Levels of tissue-type plasminogen activator had a positive correlation with von Willebrand factor antigen (r = 0.66, p = 0.008). Conclusions: Altered levels of endothelial markers in the plasma, in the presence of normal levels of d-dimer, suggest that endothelial dysfunction may precede the occurrence of intravascular coagulation and thrombosis in patients with functionally univentricular physiology. These observations may have therapeutical implications.

Over a 25-year period, we encountered 12 patients who died suddenly with coronary arterial lesions due to Kawasaki disease. We report their clinical course, and analyze the happenings of their deaths. Of the 12 patients, 10 were dead on arrival at hospital. Their age at death ranged from 13 months to 27 years, with a median of 16 years, and the interval from the onset of Kawasaki disease to death ranged from 2 months to 24 years. In 4 patients, death was found to be due to myocardial infarction, while in the remaining 8, it could not be determined. In 7 patients, coronary angiograms obtained less than 4 months after the acute onset of Kawasaki disease showed lesions bilaterally, most being giant aneurysms. Myocardial infarction had occurred in 6 patients prior to their death. In 1 patient of the late 1970s, who collapsed after running, cardiac sequels had not been suspected prior to autopsy. During the 1980s, 3 infants with bilateral giant aneurysms died within a year of the initial onset of Kawasaki disease, with acute myocardial infarction being the cause in 2 of them. In the late 1990s, and the 2000s, 5 patients died suddenly with left ventricular dysfunction, their ejection fractions being less than 40 percent more than 20 years after the initial onset of Kawasaki disease. Prior to their sudden deaths, they had had no cardiac events for many years, but had suffered previous myocardial infarctions. Multifocal premature ventricular contractions, and non-sustained ventricular tachycardia, are probable risk factors in such patients. Careful follow-up, checking for ventricular arrhythmia, is needed to prevent sudden death in patients suffering left ventricular dysfunction in the setting of Kawasaki disease.

The respiratory syncytial virus is the most common cause of infection of the lower respiratory tract in infants and young children, and is the leading cause of hospitalisation and death due to viral illness during the first year of life. In otherwise healthy infants, the virus usually causes only mild respiratory illness, but premature babies and infants with chronic lung disease, those with congenitally malformed hearts, or those who are immunodeficient, are at increased risk of serious illness, hospitalisation, and death. Recent infection with the virus is also associated with increased postoperative complications after corrective surgery for congenitally malformed hearts. No effective vaccine is currently available, and treatment is limited to supportive therapy. Prevention in groups deemed to be at high-risk, therefore, is essential. In addition to measures for control of infection, prophylactic immunotherapy is indicated in selected patients. Palivizumab (Synagis®) is a monoclonal antibody indicated for the prevention of serious viral disease of the lower respiratory tract in premature infants, those with chronic lung disease, and those with haemodynamically significant congenital cardiac lesions. Palivizumab is given intramuscularly, usually as a monthly injection during the so-called “season”. In a recent international, randomised, double-blind, placebo-controlled trial in 1,287 children less than or equal to 2 years old with haemodynamically significant congenital cardiac malformations, prophylaxis achieved a relative reduction of 45 per cent in the incidence of antigen-confirmed viral-related hospitalisation, and reduced the duration of hospital stay by 56 per cent. National and international guidelines, therefore, now recommend routine prophylaxis in the first year of life in children with haemodynamically significant congenital cardiac disease.

Cardiac and pulmonary physiology in patients with functionally univentricular hearts is markedly different from that found in the setting of the normal circulation. The physiology of both the heart and the lungs remains abnormal after palliative procedures, such as creation of systemic-to-pulmonary shunts, banding of the pulmonary trunk, or creation of the cavo-pulmonary connections. In this brief review, I will concentrate on two main aspects of physiology, namely oxygenation and haemodynamics. I will make comparisons between the normal circulation and the functionally univentricular circulation, the latter both before and after creation of a cavo-pulmonary connection. To finish, I will discuss the physiology of the cavo-pulmonary connection itself, and consider some clinical implications.

Objectives: Acute rheumatic fever and its sequel, rheumatic heart disease, is a major problem in children, adolescents and young adults. Despite the widespread application of the Jones criterions, carditis is either underdiagnosed or overdiagnosed. Echocardiography is rarely used optimally for precise diagnosis. The objective of our study, therefore, was to define the potential role of echocardiography in detecting carditis in the setting of acute rheumatic fever. Materials and methods: We performed echocardiography in 452 consecutive patients with acute rheumatic fever, clinically diagnosed by the strict Jones criterions, using the patients as part of a multi-centric and double blinded prospective study. Results: Of our 452 patients, 230 were males, and 222 were females. The youngest was aged 1 year 11 months, while the oldest was a 51-year-old female. Out of the 452 cases of acute rheumatic fever, 239 patients (52.8%) had arthritis. Out of 164 cases of clinically diagnosed carditis, only 141 cases had echocardiographic evidence of carditis (85.97%). The remaining 23 patients (14%) had functional murmurs, tachycardia, or anaemia. Of the patients, 2 also had congenitally malformed hearts. Of 40 patients with rheumatic chorea, 28 (70%) had echocardiographic evidence of carditis or valvitis. Polyarthralgia was seen in 213 cases (47.12%), from which only 38 patients (17.8%) had carditis clinically, albeit that 88 patients (41.3%) showed echocardiographic evidence of subclinical carditis or valvitis. Conclusion: Echocardiography, when carried out in patients with acute rheumatic fever diagnosed strictly according to the Jones criterion, can avoid both overdiagnosis and underdiagnosis of carditis. A high incidence of carditis, or subclinical carditis, is detected by echocardiography when performed in patients with rheumatic chorea or arthralgia.

A systemic-to-pulmonary arterial shunt is still widely used for palliation of some neonates with cyanotic congenital cardiac lesions. This procedure, however, is well known to be associated with some degree of morbidity and mortality. To reduce the incidence of iatrogenic pulmonary arterial deformities, we have devised a new and simple technique to create the shunt using a partial sternotomy, and have used our technique in 10 neonates with cyanotic cardiac malforamations. All but one of our patients survived, and an early reoperation was needed in only one further patient for revision of the shunt. Successful bidirectional Glenn procedures were performed in five of the nine surviving patients within 18 months of the initial procedure. We believe that our technique provides superior palliation by permitting equal enlargement of the right and left pulmonary arteries, and thus facilitates subsequent completion of the Fontan circulation.

The aim of the study was to evaluate segmental and global right ventricular function at rest and during stress in patients having a systemic morphologically right ventricle. We studied 17 patients after atrial correction for transposition, 13 with congenitally corrected transposition, and 11 age-matched controls using cardiovascular magnetic resonance at rest and during stress with dobutamine given at 15 micrograms per kilogram per minute. Blood was drawn to obtain levels of brain natriuretic peptide. Right ventricular ejection fraction was calculated, and wall-motion and wall-thickening were assessed, in 4 segments of a midventricular slice. The findings for the systemic right ventricle were compared to the left ventricle in controls. Patients with transposition showed a decreased ejection fraction at rest (57 percent versus 69 percent, p equal to 0.005), decreased wall motion of the anterior, lateral and septal wall (p less than 0.01, p less than 0.01, and p less than 0.01) and decreased thickening of the lateral wall (p less than 0.01). Patients with congenitally corrected transposition showed normal ejection fraction, wall thickening, and wall motion at rest. During dobutamine stress, we found no significant differences in wall motion and thickening between the two groups. Ejection fraction, also increased to comparable values during stress, at 67 percent versus 66 percent, p not being significant. In both groups, we observed similarly increased levels of brain natriuretic peptide (p equal to 0.02 and 0.03, respectively). We conclude that only patients with transposition showed segmental wall motion and wall thickening abnormalities at rest. After dobutamine stress, however, segmental and global right ventricular dysfunction was similar in both groups.

All newborn infants have limited pulmonary reserve compared with older children. This puts them at increased risk of respiratory complications, such as those associated with infection by the respiratory syncytial virus. Young children with congenital cardiac disease are particularly likely to suffer severe disease related to infection by the virus. In these children, the extreme vulnerability of the lung to pulmonary oedema is compounded by the additional burden caused by the respiratory syncytial virus.

In addition to the well-documented acute pulmonary effects of infection with the respiratory syncytial virus, there may also be consequent long-term respiratory morbidity. Clinical studies have shown that infection by the virus in infancy is associated with a higher risk of developing subsequent bronchial obstructive disease. Much debate surrounds the mechanisms underlying this association. It is thought that a combined immunological and neurogenic response mechanism is likely. Prevention of severe respiratory disease in infants and young children with congenital heart disease due to infection by the virus may, therefore, offer both immediate and long-term benefits. Indeed, an increasing body of evidence supports this hypothesis, indicating a clinical rationale for prophylaxis against the virus in infancy, in order to reduce the chance of developing reactive airways disease and asthma in later life.

The ventricle of a functionally univentricular heart is dilated, hypertrophic, and hypocontractile, certainly after the completion of a Fontan circulation (reviewed in Reference). It is difficult, however, to determine the reasons for these abnormal ventricular conditions. The abnormal size of the ventricle, along with the less than adequate function, can be due to the congenital malformation itself, the previous surgical conditions, or the very abnormal working conditions of the ventricle during the various stages of palliation. Moreover, because of the varying morphology of the pumping ventricle in patients with a functionally univentricular arrangement, it is difficult to assess size, shape, hypertrophy, stress, strain, contraction and relaxation, both in cross sectional and serial follow-up.

The provision of outreach services by paediatric cardiac centres enhances the choice for both parents and professionals. We have conducted a survey to investigate the processes for information and communication at times of interface between specialist and local services for cardiac disease. Based on the responses, we suggest that distance from, and level of contact with, the specialist centre may influence satisfaction and the perceived usefulness of more information. We suggest strategies to increase contact, and make more effective targeting of resources.

With advances in surgical technique, more children with complex congenital heart disease are surviving.1 Increasingly, attention is focusing on late morbidities, such as right ventricular dysfunction.2 For many common forms of congenital cardiac malformations, the assessment of right ventricular size and function is now essential so as to make optimal decisions concerning management.3 Commonly encountered examples include the timing for operative replacement of the incompetent pulmonary valve following surgical repair of tetralogy of Fallot, and the assessment of suspected ventricular dysfunction in children with functionally single or systemic right ventricles.4 Echocardiography remains the most practical method for serially determining right ventricular function, despite its limitations.5 The easy accessibility of echocardiography has encouraged its continued development as a tool for determining right ventricular function in neonates, infants, and children. A comparison of values established for the right ventricle is shown in Table 1, along with the references from which they were culled. We will describe these values in sequence.

Our aim was to analyze left ventricular fractional shortening during extracorporeal membrane oxygenation under the influence of changing volume loading conditions induced by a ductal left-to-right shunt. In all patients, the fractional shortening was observed using echocardiography before, during, and after bypass, irrespective of the presence or absence of the ductal left-to-right shunt. During membrane oxygenation, there was a significant decrease in fractional shortening (p less than 0.001), with no difference before and after membrane oxygenation. A greater decrease in fractional shortening was observed in the group with a ductal left-to-right shunt when compared to patients lacking the ductal shunt (p less than 0.006). The diastolic diameter of the left ventricle also increased significantly during the membrane oxygenation in those patients with left-to-right ductal shunting. Moreover, the patients with left-to-right shunting showed a very severe decreased fractional shortening, lower than 10 per cent, with significantly greater frequency (p less than 0.05) during the course of membrane oxygenation. Conclusion: An important decrease in left ventricular fractional shortening is observed during veno-arterial extracorporeal membrane oxygenation. Left-to-right shunting during bypass, as seen in the patients with patency of the arterial duct, increases the loading conditions on the left ventricle, and produces a significant increase in left ventricular diastolic dimensions. Despite the effects of volume loading produced by the ductal shunt during bypass, the decrease in fractional shortening is significantly more pronounced for these patients. Therefore, during membrane oxygenation the volume loading produced by the ductal shunt is unable to prevent a decrease in left ventricular fractional shortening.

Aims: The criterions for the timing of surgical intervention in children with rheumatic mitral or aortic valvar regurgitation are not defined. I hypothesized that, in children with chronic mitral or aortic regurgitation, an index for decompensation could be created by using the ratio of the diastolic left ventricular wall thickness to the radius, and that such an index could prove useful in determining the optimal time for surgical intervention. Methods: The left ventricular echocardiograms were obtained at the tips of the leaflets of the mitral valve by M-mode echocardiography. The diastolic septal wall thickness was measured between the right and left ventricular endocardial layers, and the posterior wall thickness between the endocardium and the interphase between the epicardium and the myocardium. The left ventricular diastolic dimension was then measured, between the posterior and septal wall endocardial layers, and systolic dimension as the smallest distance detected between these layers. All diastolic measurements were made at the time of the R wave of electrocardiogram, using the leading edge technique. The ratio of wall thickness was measured using the mean of septal and posterior wall thicknesses divided by half the diastolic dimensions, the normalized thickness of the wall previously referred to as the h/r ratio and relative mural thickness. Results: The ratio of wall thickness to left ventricular radius, and its relation to systolic left ventricular pressure or systolic blood pressure, was found to be linear in 89 normal school children, and 39 children with aortic stenosis. For future predictions, I calculated the 95th percentile limits and the 95th percentile confidence bands for this relation. Using the same data, it proved possible to calculate ratios of wall thickness for various ranges of either systolic blood pressure or left ventricular peak pressure. By using the normal limits of 0.356 plus or minus 0.0316 of the ratio, appropriate for the systolic blood pressure of children with mitral regurgitation, I determined the adequacy of the ratio of wall thickness. Of the children, 51 were in ventricular failure, and these had an inadequate ratio, below two standard deviation. Of the others, 21 had an inadequate ratio to within minus one to minus two standard deviations, and 12 of these were asymptomatic, 8 were symptomatic, but only one was in ventricular failure. For 18 children with aortic regurgitation, using the same limits, one child was within 1 standard deviation and was asymptomatic, 8 fell within minus 1 to minus 2 standard deviations and 2 of these were symptomatic, 5 were in ventricular failure, and 1 was asymptomatic, while the other 9 had ratios falling less than minus 2 standard deviations, and all were in ventricular failure. Conclusion: I conclude that the index of normalized wall thickness defined as the ratio of the left ventricular wall thickness to its radius is adequate, and within normal limits, when there is compensated volume overload, but is inadequate and below normal limits when the volume overloaded left ventricle becomes decompensated. My data suggests that the persistently decreasing ratio of wall thickness below the limits of normality serves as an indicator of ventricular decompensation, and thus can be used as a new criterion for determining the optimal time for surgical intervention.

Deteriorating ventricular function is a major concern after the Senning operation. A Doppler-derived non-geometric measurement, the so-called myocardial performance index, has been described for use in adults and children. We aimed to assess the utility of this index as a method for quantification of right ventricular function in patients in the late follow-up of the Senning procedure, and to correlate the right ventricular ejection fraction and the first derivative of right ventricular pressure as derived using echocardiography with the ejection fraction determined using magnetic resonance imaging.

We studied 44 patients within a mean postoperative period of 15.3 years. We calculated the right ventricular myocardial performance index by pulsed wave Doppler interrogation of tricuspid inflow and aortic outflow, the ejection fraction by Simpson's rule, and the first derivative of right ventricular pressure by continuous wave Doppler from tricuspid regurgitation.

Mean values of right ventricular myocardial performance index, ejection fraction, and the first derivative of right ventricular pressure were 0.50, 39 percent and 1,398 millimetres of mercury per second, respectively. A cut-off value of 0.47 for the right ventricle myocardial performance index was determined, with a sensitivity of 75 percent and a specificity of 62.5 percent. We found no correlation between ejection fraction and the first derivative of right ventricular pressure as estimated by echocardiography and the ejection fraction as shown by magnetic resonance imaging (r2 equal to 0.29 and 0.04 respectively).

We concluded, first, that patients with preserved right ventricular function had values for the right ventricular myocardial performance index lower than 0.47, and second, that ejection fraction and the first derivative of right ventricular pressure as determined echocardiographically did not correlate with values derived using magnetic resonance imaging.

Insufficiency of any of the four cardiac valves is a common cause of heart failure in children. Progression of ventricular dysfunction can be predictable, but requires thorough understanding of valvar disease. In valvar regurgitation, the heart has to cope with an increased volume of blood. The pathophysiological sequence is similar for both the right and the left heart. There is initially an increase in end-diastolic volume, followed by an increase in end-systolic volume, and at the end, a decrease in the shortening and ejection fractions. Different compensatory mechanisms and pathophysiologic adaptations develop to maintain the stroke volume for each type of valvar insufficiency, but heart failure eventually ensues. When symptoms of heart failure develop, irreversible ventricular dysfunction is often established, and outcome after surgery may ultimately be compromised. Discerning the optimal time for intervention, before irreversible ventricular dysfunction develops, is a key point in the management of regurgitant valvar heart disease.

In a prospective audit of consecutive referrals for fetal echocardiography between 1997 and 2003, we documented all instances of an abnormal arrangement of the abdominal vessels. We then established the structure of the heart in these fetuses, noting any extra-cardiac associations, and the eventual outcomes.

We found a cardiac abnormality in 572 of the 2,136 fetuses examined during this period (27 percent), with 16 (0.8 percent) having an abnormal arrangement of the abdominal great vessels. Mirror-imaged arrangement was found in 3, while the arrangement suggested right isomerism in 6, and left isomerism in 7. Of these 16 fetuses, 14 had cardiac malformations. Isomerism of the right atrial appendages was found in 7 fetuses, all with either a right-sided stomach or cardiac apex, and 6 with a common atrioventricular junction guarded by a common valve. Only 1 of these fetuses survived. Of the 3 fetuses with mirror-imaged abdominal great vessels, 2 also had mirror-imaged atrial arrangement, while the 3rd had isomeric right appendages. Only one of 7 fetuses with an abdominal great vein posterior to the aorta had bilateral left atrial appendages. The remaining 6 had usual atrial arrangement, with normal pulmonary venous connections in all but one, who had infra-diaphragmatic totally anomalous pulmonary venous connection. Of these fetuses, 2 had coarctation of the aorta, and 2 others had complex cardiac malformations resulting in neonatal death. One died in childhood from biliary atresia, and three are alive.

Abnormal arrangements of the abdominal great vessels, therefore, were found in 0.8 percent of our total fetuses, and in 2.4 percent of those with cardiac malformations. Those with an abnormal arrangement of the abdominal vessels combined with an abnormal arrangement of the atrial appendages, however, made up only 0.5 percent and 1.6 percent, respectively. While screening for an abnormal arrangement of the abdominal vessels overestimated the incidence of left, but not right, isomerism of the atrial appendages, it did predict the presence of important extra-cardiac malformations that required urgent recognition and management after birth.