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.

Objective: To document the echocardiographic features of tetralogy of Fallot during fetal and postnatal life. Correlation of echocardiographic findings with the requirement for early intervention prior to definitive repair. Design: Retrospective observational study. Setting: A tertiary fetal cardiology unit. Patients: Fetuses with a diagnosis of tetralogy of Fallot identified from a prospective database between 1 January 1999 and 31 October 2002. Main measures of outcome: Growth of aorta and pulmonary trunk during fetal and postnatal life. Doppler assessment of the great arteries both prenatally and postnatally. Clinical outcome to definitive repair. Results: We identified 25 fetuses with tetralogy of Fallot, 23 having a pulmonary valvar diameter below the normal range at some point during gestation. The ratio of the diameter of the aortic to the pulmonary valve was abnormal in all cases. The pulmonary arterial Doppler velocity was within the normal range in six fetuses at presentation, and elevated in the remainder. In two fetuses, the right ventricular outflow tract was patent during fetal life, but had become atretic at birth. Both of these fetuses had reversal of flow in the arterial duct at presentation during fetal life. In 2 fetuses in whom we showed poor growth of the pulmonary trunk in late gestation, it was necessary to intervene early. The Doppler velocity across the pulmonary valve during fetal life did not differentiate between babies who required early intervention and those who were repaired electively. There was a marked increase in pulmonary arterial Doppler velocity following birth, which became more elevated with age. Of 18 liveborn infants, 17 have survived, with 2 having balloon dilation of the right ventricular outflow tract, and 3 insertion of a Blalock-Taussig shunt prior to definitive repair. Conclusions: In tetralogy of Fallot, features of pulmonary valvar hypoplasia and obstruction are evident during fetal life. Progression of obstruction in the right ventricular outflow tract was observed during fetal life as well as postnatally. Reversal of flow in the arterial duct, and failure of growth of the pulmonary trunk, predicted the need for early surgery to maintain pulmonary blood flow. Parents should be counselled about the possibility of emergency intervention being required after birth. Affected fetuses should be delivered at units with experience of managing the cyanosed newborn.

A transient form of hypertrophic cardiomyopathy has been previously described in infants of diabetic mothers. When it occurs, it is generally benign. The purpose of our study was to establish the extent of injury to the cardiomyocytes in symptomatic and asymptomatic patients with and without hypertrophic cardiomyopathy.

Thus, we compared 35 consecutive patients to 20 healthy controls, establishing the significance, if any, of differences in cardiac troponin-I and creatine kinase, including its MB-fraction, and seeking to establish the value of these parameters in the diagnosis of cardiac injury. We also determined to levels of glucose and insulin in the serum, and took note of electrocardiographic and echocardiographic investigations. Values were determined at the 1st and 7th days after admission in the patients, while parameters were measured in the control group only on the first day.

We found that the levels of cardiac troponin-I in the serum, known to be a marker for cardiac injury, were significantly elevated in symptomatic patients with life-threatening respiratory or haemodynamic distress. We speculate that transient ventricular hypertrophy is neither the cause nor the consequence of damage to the cardiomyocytes. It would be interesting, nonetheless, to determine the relationship, if any, between cardiomyocytic damage and clinical outcome.

The appropriate timing of intervention in patients with chronic aortic incompetence allows recovery of ventricular function. We sought to determine the optimal timing of the Ross procedure for chronic aortic incompetence in young patients. We retrospectively analysed case notes, and measured pre- and postoperative echocardiographic indexes of left ventricular function, in patients who had undergone the Ross procedure for chronic aortic incompetence. Methods and results: We found 21 patients with preoperative and postoperative data suitable for analysis. Their age at operation ranged from 5.6 to 26 years, with a median of 13.8 years, and the duration of follow-up was from 0.5 to 6.8 years, with a median of 2.4 years. The preoperative left ventricular end-diastolic dimension was converted to a z-score, and this was used as a threshold to divide the population. Using the threshold of a preoperative left ventricular z-score of more than 3 to divide the population did not show any difference in postoperative parameters of left ventricular function. Significant differences were found postoperatively, however, in both the left ventricular z-score and the ratio of left ventricular end-diastolic radius to posterior wall thickness in diastole, with a cutoff preoperative threshold z-score greater than 4. Conclusion: The increase in the ratio of left ventricular end-diastolic radius to the thickness of the posterior wall in diastole would suggest that there is disruption of left ventricular short axis architecture and myocardial contractile function when intervention is postponed. The significantly larger left ventricular dimension at end-diastole, despite the reduction in volume loading post surgery, may also demonstrate irreversible structural changes. Our data would suggest that recovery of left ventricular function is less likely when the left ventricular z-score has reached the value of 4, and that, ideally, intervention should be performed when the z-score approaches or exceeds 3.

Background: Cardiac rhabdomyomas associated with tuberous sclerosis induce various abnormalities in the electrocardiogram. Electrocardiographic evidence of ventricular hypertrophy may appear if the tumour is electrically active. To our knowledge, electrocardiographic evidence of ventricular hypertrophy has been reported only in association with congestive heart failure. Follow-up studies of changes in electrocardiographic findings are also lacking. Methods: We studied 21 consecutive patients with cardiac rhabdomyoma associated with tuberous sclerosis, 10 males and 11 females, aged from the date of birth to 9 years at diagnosis. The mean period of follow-up was 53 months. None of the patients developed congestive heart failure. We evaluated the electrocardiographic changes during the follow-up, and their association with echocardiographic findings. Results: Of the 21 patients, 12 showed one or more abnormalities on the electrocardiogram at presentation, with five demonstrating right or left ventricular hypertrophy. In all of these five cases, the tumours were mainly located in the respective ventricular cavity. In one patient with a giant tumour expanding exteriorly, there was marked left ventricular hypertrophy on the electrocardiogram. Followup studies showed spontaneous regression of the tumours in 12 of 19 patients, with abnormalities still present in only 7 patients. A gradual disappearance of left ventricular hypertrophy as seen on the electrocardiogram was noted in the patient with marked left ventricular hypertrophy at presentation in parallel with regression of the tumour. Conclusions: The presence of cardiac rhabdomyomas in patients with tuberous sclerosis might explain the ventricular hypertrophy seen on the electrocardiogram through its electrically active tissue without ventricular pressure overload or ventricular enlargement, although pre-excitation might affect the amplitude of the QRS complex. Even in cases with large tumours, nonetheless, the electric potential might not alter the surface electrocardiogram if the direction of growth of the tumour is towards the ventricular cavity. In many cases, electrocardiographic abnormalities tend to disappear, concomitant with regression of the tumours.

The standard surgical approach for closed heart procedures in small infants and children is to use a posterolateral thoracotomy incision, which results in the division of the latissimus dorsi and serratus anterior muscles. The aim of our study was to determine the frequency and type of musculoskeletal deformities in children undergoing surgery with this approach for congenital cardiac disease.

We included 49 children, 28 boys and 21 girls, in the study. Their mean age was 10.2 ± 4.8 years, the mean age at the time of surgery was 3.8 ± 4.0 years, and they were evaluated at an average of 6 years after the thoracotomy. Of the patients, 94% had various musculoskeletal deformities. Scoliosis was observed in 15 patients (31%) but only in two patients did the curves exceed 25 degrees. Of these patients, three-fifths had aortic coarctation. Elevation of the shoulder was seen in 61%, winged scapula in 77%; while 14% had asymmetry of the thoracic wall due to the atrophy of the serratus anterior muscle. Deformity of the thoracic cage was observed in 18%; and 63% had asymmetry of the nipples.

Thus, we found that musculoskeletal deformities are frequent after thoracotomies in children with congenital cardiac disease. Patients who have undergone such procedures for cardiac or noncardiac surgery should be followed until their skeletal maturation is complete. Techniques sparing the serratus anterior and latissimus dorsi muscles should be preferred. These adverse effects of thoracotomy may be another reason for using interventional procedures in these cases.

We evaluated the concentrations of the brain and atrial natriuretic peptides in the plasma as markers of ventricular function and volume load in children with functionally univentricular hearts. We studied 7 children aged from 0.5 to 0.7 years with functionally univentricular hearts who had undergone a first palliative operation, and 10 children aged from 1.8 to 3.7 years who had undergone a bidirectional Glenn anastomosis at ages ranging from 0.4 to 1.0 year. As a control group, we studied 14 children without heart defects aged from 0.1 to 4.5 years. Levels of the brain natriuretic peptide were measured at 8.3 to 122 ng/l, with a mean of 52.8 ng/l, after the first palliative operation, compared to 0 to 16 ng/l, with a mean of 7.3 ng/l, after a bidirectional Glenn anastomosis, and 0 to 13.8 ng/l, with a mean of 5.9 ng/l, in the children serving as controls. Corresponding values for atrial natriuretic peptide were 17 to 203 ng/l, with a mean of 103 ng/l, after the first palliative operation, compared to 16 to 54 ng/l, with a mean of 29 ng/l, after the bidirectional Glenn anastomosis, and 12 to 52 ng/l, with a mean of 32 ng/l in the controls. Echocardiography showed that all the children with functionally univentricular hearts had normal ventricular function. Blood presssure, pulmonary arterial pressure, and arterial saturations of oxygen did not differ between the groups. We conclude, that in children with functionally univentricular hearts, the volume overload imposed on the heart after the first palliative operation is associated with increased production of brain and atrial natriuretic peptides, while after ventricular unloading, levels of the natriuretic peptides return to control values.

Background: Outcomes and costs of inpatient versus outpatient pediatric cardiac catheterization have not been extensively evaluated. Methods: For a cost-consequence analysis, we reviewed the medical records and cost data in a Swiss pediatric hospital. We compared outcomes and costs of observed inpatient management versus hypothetical planned same-day discharge for patients meeting the outpatient catheterization criterions for an American pediatric hospital. Results: Among 346 catheterization admissions occurring from January, 1998 through December, 1999, 179 met the American criterions for outpatient catheterization. Complications observed, and/or nursing interventions begun within 5 hours of catheterization, might have required overnight observation in 41 of the 179 admissions (22.9%). The remaining 138 patients were stable at five hours, and presumably could have been discharged the day of the procedure. Routine pre-discharge imaging detected significant complications following three interventional procedures. Postulated costs from the perspective of the provider, counting hospital and physician expenditure were calculated for the Swiss franc in 2000 at a rate of 1.69 francs for each American dollar, averaged 10,946 francs per inpatient, versus 9790 francs for outpatient treatment (p < 0.001 by paired t-test). Estimated revenue deficits, calculated as costs minus reimbursement, averaged 8565 francs per inpatient versus 1756 francs per patient treated as an outpatient. Conclusions: Half the patients being catheterized in the Swiss hospital met the external criterions for attempted outpatient catheterization. Most might have been safely discharged on the same day, with modest savings in costs, and reduced deficits in terms of revenue. Routine pre-discharge imaging may be more important than overnight observation. Outpatient catheterization merits prospective evaluation in Switzerland.

Objectives: We evaluated the efficacy of percutaneous transluminal coronary angioplasty for anastomotic stenosis after coronary arterial bypass grafting using the internal thoracic artery in patients with coronary arterial lesions due to Kawasaki disease. Subjects and Methods: From July 1997 to April 2000, four boys and one girl underwent percutaneous transluminal coronary angioplasty for 6 anastomotic lesions following coronary arterial bypass grafting using the left or right internal thoracic artery. Progressive severe stenosis of the grafts in the follow-up angiograms after grafting, and evidence of ischemia, were regarded as indications for percutaneous transluminal coronary angioplasty. Age at coronary angioplasty ranged from 4.2 to 16.7 years, with a median of 6.9 years, while the interval from operation ranged from 0.3 to 3.0 years, with a median of 1.1 years. The diameter of the balloon catheter employed varied from 1.5 to 2.5 mm, and the pressure of inflation ranged from 8 to 16 atmospheres. Results: The degree of stenosis decreased from 63 to 99%, with a median of 88%, to 0 to 40%, with a median of 17% immediately after angioplasty. A follow-up angiogram either 3 months or 1 year later revealed no restenosis in any patient. Conclusion: Percutaneous transluminal coronary angioplasty is a feasible and useful procedure for treating anastomotic stenosis following coronary arterial bypass grafting using the internal thoracic artery in patients with coronary arterial lesions due to Kawasaki disease.

The Helex Septal Occluder is a new device used to close atrial septal defects via interventional catheterization. In order to study the role of echocardiography during its use, and to describe the morphologic variants of defects suitable for closure with this occluder, we evaluated all patients undergoing intended closure of an atrial septal defect with the Helex occluder. A combination of transthoracic, transesophageal, three-dimensional, and intracardiac echocardiography were used before, during, and after the procedure to characterize anatomy, assess candidacy for closure, guide the device during its deployment, and evaluate results. Among the 60 candidates included in the study, 11 were excluded because of transesophageal echocardiographic and/or catheterization data obtained in the laboratory. Attempts at closure were successful in 46 patients, and unsuccessful in 3. We successfully treated four types of defects. These were defects positioned centrally within the oval fossa with appreciable rims along the entire circumference of the defect, defects with deficient or absent segments of the rim, defects with aneurysm of the primary atrial septum, and defects with multiple fenestrations. Follow-up transthoracic echocardiograms taken at a median of 7 months demonstrated no residual defects in 21, trivial residual defects in 17, and small residual defects in 8 patients. In 20 patients, three-dimensional reconstructions were used to characterize the morphology of the defect and the position of the device. Because transesophageal echocardiography was often limited by acoustic interference from the device, intracardiac echocardiography was utilized in 3 cases to overcome this limitation.

Tetralogy of Fallot is only rarely associated with aortic valvar disease. We present a child who had uncomplicated repair of tetralogy of Fallot at 16 months of age, and who developed mild aortic stenosis three years later, with mild to moderate aortic incompetence being seen two years subsequent to that event. No aortic valvar disease had been noted prior to surgery. No intervention is planned at this stage.

We report a 12-year-old girl who had multiple congenital cardiac lesions, specifically an arterial duct, left pulmonary arterial stenosis, an atrial septal defect in the oval fossa, and mild Ebstein's malformation of the tricuspid valve. Therapeutic transcatheter intervention was performed to stent the left pulmonary artery, occlude the arterial duct with a coil, and place a device to close the atrial septal defect. Subsequent to the catheterization, she complained of hoarseness, which was shown to be due to entrapment of the left recurrent laryngeal nerve between the coil used to close the arterial duct and the stent placed in the left pulmonary artery. Laryngoscopy confirmed paralysis of the recurrent laryngeal nerve.

The potential for development of 2 to 1 atrioventricular conduction in children with prolongation of the QT interval has been previously reported secondary to electrolytic disturbances. We report here a child who developed 2 to 1 atrioventricular conduction with prolongation of the QT interval following treatment with amiodarone for refractory supraventricular tachycardia. We highlight the importance of electrocardiographic monitoring to assess for those at risk of amiodarone toxicity, which may be manifested by prolongation of the QT interval and the simultaneous loss of atrioventricular conduction, and of equal importance the need for prompt conversion to an alternative anti-arrhythmic agent.

We report the interventional procedures performed on a 12-year-old child with obstruction of the right ventricular outflow tract, pulmonary valvar insufficiency, pulmonary arterial stenosis, and an atrial septal defect. A staged repair of all anomalies was performed successfully using transcatheter techniques.

We describe a patient with diffuse varices of the right pulmonary veins in association with patency of the arterial duct and an atrioventricular septal defect with separate right and left atrioventricular valvar orifices.