Introduction: There is limited data on medium to long-term outcome, and the morbidity and mortality associated with the implantation, of pulmonary arterial stents. Purpose: To assess changes in morbidity and mortality over the last two decades. Methods: Retrospective analysis of all patients stented between September, 1989 and July, 2001. Results: We implanted 664 Palmaz stents in 338 patients. The overall number included 229 patients who had undergone repair of tetralogy of Fallot, in whom 468 stents were implanted, 61 patients with congenital stenosis of the branches of the pulmonary trunk, in whom we placed 115 stents, 16 patients after an arterial switch operation who had 38 stents, and 32 patients after the Fontan operation who had 43 stents implanted. The mean age was 12.2 years, and the mean weight was 38 kg. The mean systolic pressure gradient decreased from 41 to 8.7 mmHg, the mean diameter of the stented vessel increased from 5.4 to 11.2 mm, and the ratio of right ventricular to femoral arterial pressure decreased from 0.66 to 0.45, each of these being significant at the level of p being less than 0.01. At a mean follow-up of 5.6 years, the mean gradient was 20 mmHg, the mean ratio of pressure between right ventricle and femoral artery was 0.5, and mean luminal diameter was 9.3 mm. Complications included migration of the stent in 8 patients, and pulmonary edema, hemoptysis and death in 5 patients each. There has been no mortality or morbidity since July of 1997. Technical changes include conservative serial dilations in congenital pulmonary arterial stenosis, avoidance of over-dilation, and simultaneous implantation of stents in the right and left pulmonary arteries in those with systemic pulmonary arterial pressure. Technological advances included shorter stents, improved balloon profiles, and central inflation of the stents. Conclusions: Modification of stenting practices, and increased experience of the operators over the last two decades, has virtually abolished any morbidity or mortality associated with the implantation of stents for congenital or postoperative pulmonary arterial stenoses.

To clarify the contribution of afterload to left ventricular performance after repair of mitral regurgitation, we evaluated echocardiographically 8 children who had undergone surgical repair for isolated congenital mitral regurgitation. We examined the relationship between left ventricular systolic function and preload, afterload, and contractility. The left ventricular systolic function was strongly correlated with the afterload after the surgical repair. In the postoperative state, reducing afterload by vasodilators could be a useful means of treating cardiac failure, in addition to using catecholamines to increase the contractility.

We aimed prospectively to determine the incidence of ventricular arrhythmias and ventricular late potentials in children with mitral valvar prolapse, and to assess whether signal-averaged electrocardiography could identify which such children were at high risk of developing ventricular tachycardia. In all, we examined 151 children with mitral valvar prolapse, at an age of 12.2 ± 3.1 years, and 164 healthy subjects aged 12.3 ± 3.7 years. All children underwent 24-hour ambulatory Holter monitoring and echocardiography. The children with mitral valvar prolapse were followed prospectively for a mean of 64 months. There was a significantly higher prevalence of ventricular arrhythmias in those with prolapse than in the controls (p < 0.0001). Runs of ventricular tachycardia were observed in 3 children with mitral valvar prolapse compared with one from the control group. Late potentials were more frequently observed in the children with mitral valvar prolapse than in those who were healthy (p < 0.0001), and also in those with prolapse suffering ventricular arrhythmias compared with those without ventricular arrhythmias (p < 0.02). During follow-up, 24 children with prolapsing mitral valves developed non-sustained ventricular tachycardia, giving a frequency of 3.1/100 subject-years. The sensitivity of late potentials was low, at 52%, for the identification of children with mitral valvar prolapse who developed ventricular tachycardia, although the specificity was high at 90%. This gave a positive predictive value of 50%, and a negative predictive value of 91%. We conclude that prolapse of the mitral valve predisposes to the development of ventricular arrhythmias and late potentials in children. An abnormal signal-averaged electrocardiogram is a specific, but not very sensitive, predictor for the development of ventricular tachycardia in such children.

Background: Adverse influences arising in fetal life or immediately after birth have a permanent effect on body structure, physiology and metabolism. Evidence is now accumulating that programming of bone growth might be an important contributor to the later risk of osteoporosis. Long-term morbidity and mortality associated with tetralogy of Fallot is not completely known. The aim of the present study was to evaluate the state of the bones in adolescents after surgical repair of tetralogy of Fallot, so as to ascertain any possible repercussions of the disease on bone mineralization. Material and methods: We studied 34 adolescents with repaired tetralogy of Fallot, between the ages of 11 and 18 years, to establish their nutritional status, in terms of height, weight, and skinfolds, their body composition using an anthropometric method, their sexual maturity according to Tanner, and their food-habits as based on 24-hour recall. Bone density was evaluated by lumbar dual-energy X-ray absorptiometry. We included 34 healthy eutrophic adolescents, matched for gender and age, as controls. Results: No significant differences were observed between the patients and their controls concerning nutritional status, body composition, total energy intake and nutritional supply in macronutrients, calcium, phosphorus, magnesium and vitamin D. Bone mineral density, expressed in Z-score and g/cm2, was significantly higher in patients with tetralogy of Fallot (p < 0.01). The age at the time of the first surgical procedure, or at complete surgical repair, and the total number of surgical procedures, had no significant influence on nutritional status or bone mineralization. Gender, chronological age, sexual maturity and the index of body mass are the major determinants of bone density for both samples. Obese adolescents with repaired tetralogy of Fallot had a significantly higher bone density (p < 0.05) compared to undernourished or euthrophic patients. Conclusions: Being born with tetralogy of Fallot has no significant repercussion, by the stage of adolescence, on nutritional status, pubertal progression, and accretion of bone minerals subsequent to surgical repair. Nutritional status is the major influence on the accretion of bone mass.

Background: Perceived correlation between the coronary arterial anatomy in patients with complete transposition, and the outcome of the arterial switch procedure, has made preoperative identification of their patterns standard practice. Purpose: Our purpose was to assess the accuracy of preoperative echocardiographic identification of coronary arterial patterns, to evaluate the necessity of preoperative imaging by angiography, and to determine the impact of the coronary arterial anatomy on outcome. Methods: We reviewed the medical records of all patients referred for an arterial switch operation between August 1995 and January 2000. The anatomy as described at the time of the operation using the Leiden convention was compared to the preoperative echocardiographic and angiographic findings. Results: The procedure had been performed in 67 patients, at a mean age of 9 days, with a range from 3 days to 15 months. In 42 patients, the ventricular septum was intact, while 21 patients had a ventricular septal defect, and the other four had double outlet right ventricle with the aorta anterior and rightward. In 52 patients, the left coronary artery arose from sinus #1, and the right from sinus #2. In 8 patients, the interventricular branch of the left coronary artery arose from sinus #1, with the circumflex coronary artery arising together with the right coronary artery from sinus #2. In three patients, all three coronary arteries arose from sinus #1, while in the remaining individual patients, a large conal branch arose with the left coronary artery from sinus #1, the right coronary and left anterior descending arteries arose from sinus #1, all three coronary arteries took origin from sinus #2, and the left anterior descending and right coronary artery arose from sinus #1 with no circumflex coronary artery identifiable, respectively. In two patients (4%), we identified an intramural coronary arterial course. Echocardiography and angiography were comparable (81% versus 86%) in delineating the coronary arterial anatomy. Patients with a single arterial orifice, or an atypical coronary arterial anatomy, had a slightly longer stay on the intensive care unit, and in the hospital, but showed no difference in mortality. In fact, there was no early mortality (70% confidence limits; 0–2.9%), while two patients died late (2.9%). Conclusion: We conclude that complex coronary arterial anatomy does not preclude a successful arterial switch procedure, although patients with a single coronary artery, or other arterial patterns, had a slightly longer hospital course. Preoperative echocardiographic evaluation is comparable to non-selective coronary angiography. Irrespective of complexity, nonetheless, the coronary arteries can successfully be translocated, obviating the need for preoperative coronary angiography.

Background: Paediatric cardiovascular surgery with or without cardiopulmonary bypass induces a complex pattern of pro- and anti-inflammatory responses. It is suspected that they may contribute to changes on the vascular endothelium. The endothelial response to cardiosurgical trauma and cardiopulmonary bypass, especially in children, has yet to be well established. Patients and methods: We studied 29 children undergoing cardiovascular surgery with cardiopulmonary bypass, comparing them with 21 not undergoing bypass. The groups did not differ significantly with respect to age, sex, weight and preoperative parameters. Blood samples were drawn 24 h before surgery, after onset of anaesthesia, after onset of cardiopulmonary bypass and after rewarming in those undergoing bypass, or immediately after surgery in the control group, 4 h and 2 days after surgery, at discharge, and months after surgery during out-patient follow-up. Serum levels of soluble E-selectin, P-selectin and P-selectin glycoprotein ligand-1 were measured by enzyme-linked immunoassay. Results: Paediatric cardiovascular surgery leads perioperatively to the significant decreases of the serum levels of soluble P- and E-selectin, as well as of soluble P-selectin glycoprotein ligand-1 (all p < 0.05). The time course, and all concentrations, of these molecules were not significantly different with and without bypass. The decreases, however, were more pronounced with cardiopulmonary bypass. Preoperative baseline values were reached months after surgery. Conclusion: Endothelial activation of release of adhesion molecules is reduced during paediatric cardiovascular surgery. Endothelial activity is more perturbed with cardiopulmonary bypass and for a long time after surgery.

Knowledge of normal aortic dimensions is important in the management of children with aortic disease. So as to define such dimensions, we undertook a retrospective review of clinical data and aortic cineangiograms from 167 subjects without aortic disease having a mean age of 3.67 years, with a range from 0.01 to 14.95 years. Amongst the patients, 56 were without detectable cardiac lesions, 66 patients had mild pulmonary stenosis, 30 were seen with Kawasaki disease, and 15 with small interatrial defects within the oval fossa. Aorto-grams were available in all. No patient had any hemodynamic derangement that would have affected the aorta during intrauterine life or childhood. Systolic dimensions were measured in the ascending and descending aorta at the level of the carina, at the transverse aortic arch distal to the brachiocephalic, of the left common carotid artery at its origin, at the transverse aortic arch distal to the left common carotid artery, at the aortic isthmus, and of the aorta at the level of the diaphragm. A regression analysis model was used to establish the range of predicted normal values, with their confidence limits, standardizing the values to height as the biophysical parameter having the highest correlation to aortic dimensions. Normal ranges were established for all the levels of measurement. The data should prove useful in identifying abnormalities of the thoracic aorta during childhood, and when assessing the outcomes of interventions.

Objectives: We have compared mortality and risk factors for late deaths in patients with tetralogy of Fallot undergoing surgical repair in 1972 and 1982 in a Japanese multicentric study, examining in particular the impact of time of repair. Background: There is limited information on the effect that time of repair, and our constantly changing approach to it, has on late outcome in repaired tetralogy of Fallot. Methods: We analysed the Japanese registry of deaths occurring after surgical repair of tetralogy of Fallot. We studied two postoperative 1-year cohorts of survivors of surgery performed in 12 centers. Of the patients, 122, aged 29 ± 12 years, had undergone repair in 1972, their age at repair being 9.6 years. An additional 186 patients, aged 23 ± 8.7 years, had been repaired in 1982 at the age of 7.7 years. Results: Annual mortality, as judged per 100,000 population of patients with tetralogy of Fallot, declined from 0.387 in 1972 to 0.196 in 1982. Significant differences were deaths following surgery (27% vs. 13%, p < 0.001), patching of the subpulmonary outflow tract (48% vs. 89%, p < 0.001), and transjunctional patching (13% vs. 63%, p < 0.001). Late death was observed in 6 vs. 3 patients (9/308, 2.9%). The actuarial rate of survival calculated over 14 years was 97% vs. 98%. Reoperation was performed in 5 vs. 9 patients (14/308, 4.5%). Risk factors for late death were age at repair (p = 0.01), and history of reoperation (p < 0.001). Transjunctional patching (p = 0.01) proved to be associated with late mortality only in patients repaired in 1972. Conclusions: Late survival was excellent, with a low incidence of reoperations in both groups of patients. The era of repair has a big influence on total and operative mortality, but has only a small impact on late mortality. Ongoing analysis of follow-up will possibly reveal subsequent changes with time.

Adequate nutrition is crucial to the management of children and infants with cardiac disease. Difficulties with feeding are extremely common, and maintaining an adequate caloric intake, in order to achieve sustained growth, is often not possible without nutritional support. We retrospectively reviewed our experience between 1995 and 1999 in treating 37 children with cardiac disease who underwent percutaneous endoscopic construction of a gastrostomy to augment nutritional needs. We stratified the patients into those with cyanotic heart disease, when saturations of oxygen were less than 95%; those with non-cyanotic heart disease with saturations greater than 95%, and those with minor cardiac disease associated with a systemic disorder. Each group was compared to control children matched for age, sex, and diagnosis. We evaluated the variation in standard deviation score for body weight over a median period of follow-up of 295 days. Improvements in the standard deviation score for body weight occurred in each of the groups, whereas children in the control groups demonstrated a decrease in standard deviation score for body weight. The median change of the score for body weight was significantly higher in patients managed with gastrostomy compared to controls. We conclude that supplementation using a gastrostomy tube allows the safe delivery of the caloric intake needed to support malnourished children with cardiac disease.

We assessed the thickness of the normal left ventricular wall according to gender by performing twodimensional echocardiography in children. While a few studies have evaluated left ventricular wall thicknesses in children using two-dimensional echocardiography, there is little information related to the influence of gender throughout childhood. We evaluated 251 patients (128 males and 123 females) with innocent murmurs but without congenital heart anomalies, or coronary artery lesions or arrhythmias, as determined by repeated echocardiographic, and electrocardiographic examinations. Intra-ventricular septal thicknesses at end-diastole and end-systole, and left ventricular posterior thicknesses at end-diastole and end-systole were determined in the parasternal short-axis view. Significant gender differences were observed in the thickness of all four measurements. There was a linear relationship between the thickness of the left ventricular wall and height. Height was the most appropriate and practical index for assessing the thickness of the wall of the left ventricle in children.

Purpose: We investigated the quality and usefulness of spiral computed tomography and threedimensional reconstruction in children with obstruction of the central airways as a complication of congenital heart disease. Materials and methods: Spiral computed tomography with three-dimensional reconstruction was performed in 49 children with obstruction of the central airways seen as a complication of congenital heart disease. Spiral scanning was performed during breathing in 40, and after sedation with chloral hydrate in 38. Contrast medium was administered through a pedal venous route in 42. We analyzed the motion artifact, additional information provided by, and clinical usefulness, of the three-dimensional images. We also investigated the factors influencing the quality of the images. Results: Stenoses were seen in the trachea in 21 patients, and in bronchuses in 28. Their causes were an anomaly of the aortic arch in 6, posterior displacement of the aortic arch in 7, posterior displacement of the ascending aorta in 5, compression of the brachiocephalic artery in 5, absent pulmonary valve syndrome in 6, displaced or dilated cardiovascular structure in 17, and pulmonary arterial sling in 2. Motion artifact caused mild or negligible degradation of images in all patients except 6. Breath-holding in non-sedated children produced more severe motion artifact than did cardiovascular pulsation. Threedimensional images provided additional information over two-dimensional images in 11, and provided clinically useful information in 10. Contrast injection via the pedal route was better for the quality of threedimensional images than brachiocephalic injection (p = 0.013). Conclusions: Three-dimensional computed tomography is useful in evaluation of obstruction of the central airways in children with congenital heart disease. Despite the fact that motion artifact is unavoidable, the quality of three-dimensional images is acceptable for making a proper and accurate diagnosis. A pedal route is recommended for injection of contrast medium.

Discordant atrioventricular connections associated with Wolff-Parkinson-White syndrome increase the challenge of radiofrequency ablation. We report the results and techniques of radiofrequency ablation in three patients with discordant atrioventricular connections, including one patient having double outlet right ventricle with atrioventricular reentry tachycardias. There were two males and one female, aged 14 and 22 years old. We found four accessory pathways during our electrophysiological studies, with two of them manifest on the electrocardiogram, corresponding to left paraseptal and right midseptal regions. The electrophysiological study confirmed this localization, and showed two concealed accessory pathways in the right and left paraseptal regions. Radiofrequency ablation was successful in all cases without recurrence at a mean follow-up of 18.6 months. No complications were observed during the procedures. We conclude that radiofrequency ablation is feasible and effective in the ablation of accessory pathways in patients with discordant atrioventricular connections.

In adults with Wolff-Parkinson-White syndrome, the likelihood of sudden death can be estimated based upon the presence or absence of symptoms. Comparable data in children do not exist. To date, therefore, invasive risk stratification has been used to guide management regarding radiofrequency ablation in symptomatic children. As the safety of electrophysiology study and radiofrequency ablation in children has improved, asymptomatic patients have been referred more commonly for invasive risk stratification. We sought to compare the findings from electrophysiologic studies in symptomatic children with Wolff-Parkinson-White syndrome to the findings in asymptomatic children with Wolff-Parkinson-White pattern on their electrocardiogram. Thus, we compared the findings from electrophysiologic studies carried out in patients seen at Stanford University and University of California, San Francisco, from April 1999 to February 2001 with a preexcitation pattern on their electrocardiogram. The patients were divided into three groups: 23 asymptomatic patients studied for risk stratification, 19 patients who presented with syncope, and 77 patients presenting with documented supraventricular tachycardia. Data were collected for commonly accepted invasive criterions for stratification of risk: an effective refractory period of the accessory pathway less than 270 ms, multiple pathways, septal location of pathway, and inducibility of supraventricular tachycardia. Groups were compared by chisquare. No differences were found between the groups for any of the variables. These data suggest that risk factors for sudden death, developed in studies of adult patients, are not clearly applicable to children. Further studies are needed better to define the indications for study and ablation in children.

Pulmonary regurgitation and older age at the time of repair may have a large impact late after repair on subsequent mortality of patients with tetralogy of Fallot. We aimed to identify whether age at repair, and preservation of the pulmonary valve, had a favorable influence on morbidity and mortality. We also analyzed risk factors for late death subsequent to surgical repair. We identified 167 patients who, between 1965 and 1975, and at a mean age of 6 years, underwent total repair of tetralogy of Fallot by a single surgical team without use of an outflow patch. All patients were known to have survived for at least 30 days after repair, and late mortality was identified though the use of hospital records, interviews, and death certificates. The 29-year actuarial survival rate was 86%, with 24 late deaths. Of these deaths, seven occurred suddenly (4.2%). Morbidity was analyzed in 99 of the patients by means of a written questionnaire and telephone interview. It proved possible to analyze ventricular and valvar function in 50 of the patients. Survivors experienced no re-intervention, and 89% of them were in class I of the grading system of the New York Heart Association. We found evidence of 3 episodes of sustained ventricular tachycardia (3.0%), and two episodes of atrial tachycardia (2.0%). Of the 50 patients in whom serial examinations were available, 18 had pulmonary regurgitation of moderate degree or greater, and none had more than moderate tricuspid regurgitation, with a mean QRS duration of 148ms and an ejection fraction for the left ventricle of 50%. Older age at repair (p = 0.03), and longer periods of cardiac arrest during repair (p = 0.02), were associated with late mortality. Although the mortality was similar to that observed in previous reports, our operative method might have a better effect in terms of late morbidity.

A number of cytokines have been implicated in the pathophysiology of congestive heart failure. Genetic polymorphisms of several cytokine genes are known to result in altered gene expression, enabling us to characterize patients as "high" or "low" producers of specific cytokines. We speculate that the cytokine genotypes for a population of children who underwent heart transplantation for end-stage ventricular failure due to cardiomyopathy or congenital heart disease would be enriched for "high producers" of pro-inflammatory cytokines and "low producers" of anti-inflammatory cytokines. Methods: Cytokine genotyping was performed for the following cytokines on 94 transplanted children using polymerase chain reaction-sequence specific technique: tumor necrosis factor-α (−308), interleukin 10 (−1082, −819, −592), interleukin 6 (−174), transforming growth factor-β1(codons 10 & 25), and interferon-γ (+874). Patients with ventricular failure after transplantation for dilated cardiomyopathy, numbering 37, or for congenital heart disease, numbering 34, were compared to 15 children transplanted for structural disease, such as hypoplastic left heart syndrome, without ventricular failure, and to data from healthy children. An additional 8 children with restrictive or hypertrophic cardiomyopathy were also studied. Results: No differences in genotypic distribution were seen between the groups, and all patients were comparable to genotypic distributions as assessed from published normal data. Conclusion: No evidence is found to support the hypothesis that these polymorphisms for cytokine genes influence progression to end-stage heart failure in children undergoing transplantation because of cardiomyopathy or congenital heart disease.

On the basis of our clinical experience, we hypothesized that the role of mitral valvar anomalies in the development and recurrence of discrete subaortic stenosis might be underestimated. From January 1994 to October 2000, the anatomy of the mitral valve and its relationship to the other components of the left ventricular outflow tract were studied by echocardiography in a series of 73 consecutive patients referred to our institution for surgical correction of discrete subaortic stenosis. In all patients for whom it was considered advisable, surgical correction of the mitral anomaly was performed, together with resection of the fibro-muscular subaortic stenosis. One or more mitral valvar anomalies were found in 35 patients (48%). They could be grouped into five categories: insertion of a papillary muscle into the aortic leaflet, insertion of a papillary muscle into the ventricular wall, “muscularization” of the subaortic portion of the aortic leaflet, anomalous insertion of the valvar tissue into the ventricular wall, and accessory valvar tissue. In all cases with anomalous mitral valvar anatomy, surgical correction was feasible. It consisted of transection of the anomalous papillary muscle or its attachment, resection of accessory valvar tissue, and/or patch enlargement of the aortic leaflet. The incidence of mitral valvar anomalies associated with subaortic stenosis is probably underestimated. Our data suggest that they should be systematically searched for during the evaluation of all cases of subaortic stenosis. Their surgical correction is generally feasible, and might improve the mid and long term results.

Background: We analysed the experience with hypertrophic cardiomyopathy in two paediatric centres to establish the differences from older patients. Methods: Out of 45 young patients seen from 1974 to 1999, we included 38. Criterions for exclusion were secondary forms, or association with severe congenital cardiac disease which could alter the outcome. Results: The patients presented at the age of 5.7 years, and were followed for 7.0 years. The 34 patients referred because of a murmur or cardiomegaly were older than the four with heart failure, presenting at 6.2 as opposed to 2.1 years of age, p = 0.08. Of the patients, 29 (76%) had primary cardiomyopathy, while 9 (24%) had secondary forms associated with Noonan's and LEOPARD syndromes. Familial tendency was ascertained in 7 patients (18%). The septal thickness in mm/m2 at presentation was greater in patients under 2 years than in older children (29 vs 18, p = 0.02). Obstructive hypertrophic cardiomyopathy was found in 17 patients (45%), with six of these having mild associated congenital cardiac defects. Nine had symptomatic arrhythmias. Overall, treatment was medical in 31, with DDD pacing used in 5, and surgery, radiofrequency ablation, and transplantation in one patient each. Total mortality was 24%, at a rate of 4.3% per year. Four patients died in heart failure and 5 had sudden death. Those in failure were significantly younger (p = 0.01). Conclusions: Hypertrophic cardiomyopathy in the young is characterized by referral for murmur or heart failure; frequent secondary forms; the obstructive variant being as common as the nonobstructive form; a mortality rate similar to that for adults attending tertiary centres; and less frequent familial forms than in older populations.