In this issue of the Journal, we publish three important papers concerned with rheumatic fever. So as to put these contributions in their world-wide perspective, I asked Cleonice Mota, a member of our Editorial Board, if she would prepare the “From the Editor” section for this issue. It is our pleasure to publish her thoughtful introduction, and we thank her for her continuing efforts on our behalf.

Robert H. Anderson

In this review, we discuss current concepts in the pathogenesis and management of pulmonary hypertension affecting infants and children, with special focus on left-to-right shunting, bronchopulmonary dysplasia, and primary pulmonary hypertension.

In patients of these ages, functional aspects, such as an imbalance between vasoconstricting and vasodilating mechanisms, and morphological alterations of the vessel wall, contribute to the pulmonary hypertension. In the past decades, strategies have emerged for treatment that are targeted at the pathophysiological basis. Thus, in patients with left-to-right shunting and pulmonary hypertension after intra-cardiac repair, treatment with nitric oxide has been introduced effectively, while treatment with prostanoids, such as iloprost, is under investigation. In patients with pulmonary hypertension and bronchopulmonary dysplasia, therapeutic strategies focus on the underlying chronic lung disease and use of vasodilators. The pathogenesis of primary pulmonary hypertension in children remains as yet unclear, although treatment with prostanoids has proven effectively to improve the long-term prognosis.

Right ventricular function is of great importance in patients with both acute and chronic ventricular overload. The early detection of right ventricular dysfunction may have an impact on therapeutic decision making, helping to prevent or further delay functional deterioration of the right ventricle.

In patients with right ventricular overload due to congenital cardiac diseases, dobutamine stress testing combined with magnetic resonance imaging, electrocardiographic changes, and monitoring of concentrations of plasma brain natriuretic peptide are very suitable parameters for the early detection of ventricular dysfunction, and should therefore be used in the follow-up of these patients.

It is apparent that no single measurement of anatomy or function can ever adequately describe the form or performance of the right ventricle. Rather, we should be looking more towards an integrated approach of different parameters for right ventricular function. The quantitative parameters described in this study can serve this purpose. The strong correlation found between these non-invasive and independent parameters encourages their clinical implementation.

Carditis is the only manifestation of acute rheumatic fever that leads to permanent disability. Hence, its diagnosis is of paramount importance. Recently, it has been reported that Doppler echocardiography has disclosed subclinical valvar regurgitation in some patients with acute rheumatic fever manifested as isolated arthritis or pure chorea. The prognosis of such patients with acute rheumatic fever and subclinical valvitis is not clear. We aimed, therefore, prospectively to investigate the potential to diagnose patients with subclinical carditis. We examined 40 patients, aged from 7 to 16 years, with Doppler evidence of mitral and aortic regurgitation, but in the absence of any pathologic murmur. The major findings satisfying the Jones criterions were arthritis in 29 patients, chorea in 10 patients, and arthritis and erythema marginatum in one patient. Of the patients, 33 had mitral regurgitation, 6 patients had combined mitral and aortic regurgitation, and one patient had aortic regurgitation. The patients were followed over a mean period of 18.1 ± 13.9 months, the valvar regurgitation disappearing in 23 (57.5%). No significant differences were observed in the resolution of the valvitis between those treated with acetylsalicylic acid, steroids, or those receiving no treatment. It is noteworthy, nonetheless, that patients treated with steroids were the fastest to recover from valvitis (p < 0.05).

Based on our study, we suggest that subclinical valvitis demonstrated by echocardiography should now be accepted as adequate evidence for the diagnosis of carditis, and become a major diagnostic criterion for acute rheumatic fever. When managing this group of patients with subclinical disease, treatment with steroids seems to have a role in promoting early resolution of the valvitis.

Objectives: To investigate the indications for, and outcome of, cardiac catheterisation in infants weighing less than 2500 g at a single institution over an 8-year period. Patients and Methods: We assessed all infants who were less than 2500 g at the time of cardiac catheterisation at Texas Children's Hospital from January 1993 to January 2001. Comparisons of morbidity and mortality were drawn with an equivalent number of infants of similar age weighing greater than 2500 g seen over the same period of time. Results: We performed interventional procedures in 22, and diagnostic catheterisations in 12 infants weighing less than 2500 g. Interventions included pulmonary valvoplasty in six patients, balloon angioplasty of critical coarctation in one, aortic valvoplasty in two, septostomy in ten, and coil occlusion of an arteriovenous malformation, redirection of a subclavian venous line, and coil occlusion of a patent arterial duct in one patient each. The median age at catheterisation was 5 days for children less than 2500 g, and 10 days for those above 2500 g. The median weights were 2.3 kg and 3.3 kg, and the median gestational ages were 35 weeks and 38 weeks, for the two respective groups. Of those weighing less than 2500 g, two died (6%), with no deaths occurring in those weighing more than 2500 g. In 3 patients weighing less than 2500 g (9%), there was vascular compromise, one child with bilateral femoral venous obstruction requiring fasciotomy compared, to one in the group weighing greater than 2500 g (2%). Conclusion: There is a significantly increased risk of mortality and vascular compromise in infants weighing less than 2500 g. Interventional catheterisation in these infants may be lifesaving, but given the aforementioned risks, diagnostic catheterisation should be deferred if possible in favor of noninvasive modalities.

In all patients undergoing cardiac surgery, the effective delivery of oxygen to the tissues is of paramount importance. In the patient with relatively normal cardiac structures, the pulmonary and systemic circulations are relatively independent of each other. In the patient with a functional single ventricle, the pulmonary and systemic circulations are dependent on the same pump. As a consequence of this interdependency, the haemodynamic changes following complex palliative procedures, such as the Norwood operation, can be difficult to understand.

Comparison of the newly created surgical connections to a simple set of direct current electrical circuits may help the practitioner to successfully care for the patient. In patients undergoing complex palliations, the pulmonary and systemic circulations can be compared to two circuits in parallel. Manipulations of variables, such as resistance or flow, in one circuit, can profoundly affect the performance of the other circuit. A large pulmonary flow might result in a large increase in the saturation of haemoglobin with oxygen returning to the heart via the pulmonary veins at the expense of a decreased systemic flow. Accurate balancing of these parallel circulations requires an appreciation of all interventions that can affect individual components of both circulations.

Endomyocardial biopsy in children remains important in the evaluation of cardiomyopathy, myocarditis, and rejection following cardiac transplantation. We sought to evaluate the morbidity associated with endomyocardial biopsy on the basis of a large experience from a single institution.

We reviewed records of all endomyocardial biopsies performed at our institution. Complications were defined as adverse events resulting from the biopsy requiring intervention or additional observation. We also reviewed the most recent echocardiogram from all the patients for the presence and severity of tricuspid valvar regurgitation.

Between November 1986 and April 2002, we performed 1051 endomyocardial biopsies in 135 patients ranging in age from 9 days to 18 years. The internal jugular vein was the site of vascular access in 68% of the procedures. There were 10 acute procedural complications requiring intervention or additional observation. Severe tricuspid regurgitation developed in two patients who had undergone multiple biopsies after cardiac transplantation, one of whom underwent subsequent replacement of the tricuspid valve. There were no deaths or cardiac perforations. The total incidence of morbidity was 1.1%. No demographic or procedural factors were identified to be predictive of complications.

In experienced hands, therefore, endomyocardial biopsy can be safely performed in children with very low morbidity.

Recent technical improvements in cross-sectional echocardiography have made it possible to detect even mild organic regurgitation of the mitral and aortic valves in patients with acute rheumatic fever. To determine the prevalence and prognosis of subclinical valvitis, we have analyzed 104 patients with acute rheumatic fever referred to our institution. Of 53 patients who had no murmur, 22 of them with polyarthritis, 29 with chorea, and 2 with polyarthritis and chorea, 23 (43.4%) had subclinical valvitis. Isolated mitral regurgitation was the most common valvar lesion, seen in 82.6% of the patients. Isolated aortic regurgitation was detected in 4.4% of the cases, and combined mitral and aortic regurgitation in the remaining 13%. During follow-up, the degree of mitral regurgitation improved in 59.1%, decreased in 18.2%, and increased or remained unchanged in 22.7% according to the length of colour jet. According to criterions of velocity, mitral regurgitation improved in 86.4% of the patients, and increased or unchanged in the remaining 13.6%. Mitral regurgitation disappeared completely in 6 of the patients (27.3%) as judged according to both the length of colour jet and the velocity of regurgitation. Aortic regurgitation improved in all the patients with this problem, disappearing completely in two of the four.

Based on this experience, we suggest that not only the disappearance of regurgitation, but also improvements in the echocardiographic diagnostic criterions of regurgitation, such as the length of the colour jet less than 1 cm, or velocity less than 2.5 m/s, or indicative of regurgitation that is either intermittent or of short duration, should also be considered as criterions indicating improvement in valvar regurgitation in patients with subclinical rheumatic valvitis.

The purpose of our paper is to assess the prognostic value of balloon occlusion as a test for patients with various types of functionally single ventricle after different palliative surgical procedures who were candidates for further modifications of a cavo-pulmonary operation. In all patients, there were at least two sources of pulmonary arterial supply.

Our hypothesis was that, using balloon occlusion temporarily to produce changes in the haemodynamic situation, we could simulate the potential state subsequent to surgical palliation. We used balloon occlusion in 19 patients during diagnostic catheterisation, followed by interventional and or surgical procedures as considered necessary. This test was applied for temporary closure of the pulmonary valve in 8 patients, and a Blalock-Taussig anastomosis in 11 patients.

Background: Little is known regarding parental preference for a one-stage complete repair versus a two-staged approach with initial palliation, followed by repair, of the congenital cardiac malformation. Methods: We interviewed 103 parents of healthy children referred to a clinic for pediatric cardiology. Participants were presented with a hypothetical scenario in which their children had a cardiac lesion requiring surgery. The surgery could be performed either by means of one-stage complete repair, or using a two-stage approach, with palliation first followed by complete repair a year later. The mortality rate for the one-stage repair was set at 5%. Participants were asked to choose between the one- and two-stage approaches, with differing mortality rates for the two-stage approach. The scenarios included options when the two-stage combined mortality rate was lower than the one-stage mortality, and the first stage mortality rate was at 1% and 3%, and when the two-stage combined mortality rate was the same as that for one-stage mortality, these being set at 1% and 3%. Results: When the two-stage combined mortality rate was lower than that of the one-stage repair, participants were more likely to choose the two-stage approach if the first stage mortality rate was 1% as compared to 3% (57% and 44%, respectively, p = 0.04). When the two-stage combined mortality rate was the same as the one-stage approach, participants choosing the two-stage approach when the mortality rate was set at 1%, and when it was raised to 3%, were not significantly different (42% and 34%, respectively, p = 0.24). When the combined two-stage mortality was the same as that set for one-stage repair, participants with no insurance were less likely to choose the two-stage approach than those covered by insurance (p = 0.03). Conclusions: In the chosen scenarios, when the mortality for a two-stage combined approach is the same as that for one-staged repair, more parents choose the one-staged repair. If the two-stage combined mortality is lower than that for one-staged repair, parents are more likely to choose the two-stage repair if the mortality for the first stage is lower. When the mortality rates for the one-stage and two-stage approaches are the same, people without insurance are more likely to choose one-staged repair.

In patients who have undergone a superior cavopulmonary anastomosis, the superior caval venous flow provides the only, or the most important, pulmonary blood supply, while the inferior caval venous blood is not oxygenated, being mixed with the pulmonary venous blood before entering the systemic circulation. In healthy children, the contribution of superior caval venous flow to total cardiac output has been shown to decrease during growth. Patients who have undergone a superior cavopulmonary anastomosis, however, often have a higher oxygen saturation than predicted by the age-matched ratio of superior to inferior caval venous flows. This study was designed, therefore, to assess the ratio of flows in the superior and inferior caval veins subsequent to a superior cavopulmonary anastomosis. We carried out 18 magnetic resonance imaging studies with velocity-mapping and heart catheterisations so as to assess the contribution of superior caval venous flow to total cardiac output. Patients were divided into 3 groups according to their age. There were five aged from 8 to 24 months, eight aged from 24 to 48 months, and five older than 48 months. No significant difference could be found in the ratios of superior-to-inferior caval venous flow, nor of superior caval venous-to-systemic flow, between the 3 groups. The ratio of venous flows was 0.89 ± 0.34 in those aged from 8 to 24 months, 1.09 ± 0.42 in those from 24 to 48 months, and 1.25 ± 0.27 in the older patients (F analysis of variance 1.06, p 0.37). The ratio of superior caval venous-to-systemic flow was 0.46 ± 0.08 in the youngest patients, 0.50 ± 0.09 in those aged from 24 to 48 months, and 0.55 ± 0.05 in the older patients (F analysis of variance 0.76, p 0.49). These findings suggest that the hemodynamics of a cavopulmonary anastomosis may affect the normal decrease of superior caval venous flow with age. This could be related to a redistribution of flow, with a proportionally higher flow to the head and upper body after construction of a superior cavopulmonary anastomosis. Since increasing cyanosis and progressive exercise intolerance are the main indications for creation of a total cavopulmonary connection, these findings should be taken into account when determining the timing for completion of the Fontan circulation.