Treprostinil in advanced experimental pulmonary hypertension: beneficial outcome without reversed pulmonary vascular remodeling.

Introduction: Beneficial effects of treprostinil, a stable prostacyclin analogue, were demonstrated in patients with pulmonary arterial hypertension (PAH). Although regression of pulmonary vascular remodeling has been suggested as therapeutic mechanism, its mode of action remains unknown.

Methods: Flow-associated PAH was created in rats by injection of monocrotaline (60 mg/kg) combined with an abdominal aortocaval shunt.

Prostacyclin therapy increases right ventricular capillarisation in a model for flow-associated pulmonary hypertension.

Pulmonary hypertension, and consequently right ventricular failure, complicates several congenital heart defects. Although intervention in the prostacyclin-thromboxane ratio is known to improve outcome, the underlying mechanism is not clear. Therefore, effects of acetyl salicylic acid and iloprost are studied in an animal model for flow-associated pulmonary hypertension.

A randomized, placebo-controlled GH trial in very preterm infants who were at risk for bronchopulmonary dysplasia and were treated with dexamethasone.

Very preterm infants who develop bronchopulmonary dysplasia are often treated with dexamethasone (DEXA) to wean them from the ventilator. As DEXA has growth-suppressive and catabolic effects, which might have long-term consequences on growth and organ development, we investigated whether high-dose GH treatment could overcome these effects. In a randomized, double-blind, placebo-controlled trial, 30 ventilated very low birth weight infants were assigned to receive either GH or placebo treatment after start of DEXA.

The role of increased pulmonary blood flow in pulmonary arterial hypertension.

Chronic increased pulmonary blood flow is considered a pre-requisite for the induction of advanced vascular lesions in pulmonary arterial hypertension in congenital heart defects. The aim of the present study was to characterise the effects of increased pulmonary flow induced by an aortocaval shunt in the monocrotaline rat model for pulmonary hypertension in terms of survival, haemodynamics, pathology and histology. Male Wistar rats were injected with monocrotaline followed by the creation of an abdominal aortocaval shunt.

Development of left atrioventricular valve regurgitation after correction of atrioventricular septal defect.

Background: Left-sided atrioventricular valve regurgitation is the main indication for reoperation in patients after repair of both partial and complete atrioventricular septal defect. Until now, the timing for reoperation is difficult. We sought to determine the outcome of severe residual left-sided atrioventricular valve regurgitation, either medically treated or reoperation.

Long-term intravenous treatment of Pompe disease with recombinant human alpha-glucosidase from milk.

Objective: Recent reports warn that the worldwide cell culture capacity is insufficient to fulfill the increasing demand for human protein drugs. Production in milk of transgenic animals is an attractive alternative. Kilogram quantities of product per year can be obtained at relatively low costs, even in small animals such as rabbits.

A broad and strong humoral immune response to donor HLA after implantation of cryopreserved human heart valve allografts.

Cryopreserved human heart valves are used for valve replacement in patients with congenital or acquired heart disease. Although no blood group or human leukocyte antigens (HLA) matching is performed and no immunosuppression is administered, the clinical results are relatively good. After valve replacement, the majority of the patients develop HLA antibodies, whereas a smaller group of patients shows valve-related events at the long term after right ventricular outflow tract reconstruction.

Pulmonary arterial wall distensibility assessed by intravascular ultrasound in children with congenital heart disease: an indicator for pulmonary vascular disease?

Background: Both pulmonary hypertension and pulmonary overflow are associated with functional and structural changes of the pulmonary arterial wall. Current techniques to evaluate the pulmonary vasculature neglect the pulsatile nature of pulmonary flow.

Study Objectives: To determine whether the dynamic properties of the pulmonary arterial wall are altered in patients with abnormal pulmonary hemodynamics due to congenital heart defects, and whether these changes are associated with the progression of pulmonary vascular disease (PVD).

Is there a place for pediatric valvotomy in the autograft era?

Objective: Valvotomy and the autograft procedure are the most common surgical treatment options for children with valvular aortic stenosis. We evaluated the results of these surgical procedures in our institution.

Methods: Retrospective analysis was done of all patients presenting with aortic stenosis and operated upon before the age of 18.

Right ventricular outflow tract reconstruction with an allograft conduit.

Background: Allograft conduits are used for reconstruction of the right ventricular outflow tract in patients with congenital heart disease and in the pulmonary autograft procedure. A retrospective evaluation of our experience with the use of allograft conduits for reconstruction of the right ventricular outflow tract was conducted.

Methods: Between August 1986 and March 1999, 316 allografts (246 pulmonary, 70 aortic) were implanted in 297 patients for reconstruction of the right ventricular outflow tract.

Recombinant human alpha-glucosidase from rabbit milk in Pompe patients.

Pompe's disease is a fatal muscular disorder caused by lysosomal alpha-glucosidase deficiency. In an open-label study, four babies with characteristic cardiomyopathy were treated with recombinant human alpha-glucosidase (rhGAA) from rabbit milk at starting doses of 15 mg/kg or 20 mg/kg, and later 40 mg/kg. The enzyme was generally well tolerated.

[Interventional catheter occlusion of the atrial septal defect of the secundum type--experiences with "CardioSeal" and "Angel Wings"].

Between July 1996 and July 1998, 34 patients (female n = 16, male n = 18) were scheduled for catheter--interventional occlusion (ASDO) of an atrium septum defect of secundum type (ASD II). Median age was 7.9 years (2.

The effects of long-term growth hormone treatment on cardiac left ventricular dimensions and blood pressure in girls with Turner's syndrome. Dutch Working Group on Growth Hormone.

Objective: To assess the effects of long-term growth hormone (GH) treatment for short stature on left ventricular (LV) dimensions and systemic blood pressure (BP) in girls with Turner's syndrome without clinically relevant cardiac abnormalities.

Study Design: LV dimensions measured by echocardiography and systemic BP were assessed before and during 7 years of GH treatment in 68 girls with Turner's syndrome participating in a randomized dose-response study. These previously untreated girls, age 2 to 11 years, were randomly assigned to 1 of 3 GH dosage groups: group A, 4 IU/m(2)/d; group B, first year 4 IU/m(2)/d, thereafter 6 IU/m(2)/d; group C, first year 4 IU/m(2)/d, second year 6 IU/m(2)/d, thereafter 8 IU/m(2)/d.

Three-dimensional echocardiography enhances the assessment of ventricular septal defect.

By 3-dimensional echocardiography, the location, relation to the aortic and tricuspid valve, and the size of the ventricular septal defect was assessed and compared with 2-dimensional echocardiography and intraoperative findings. We concluded that 3-dimensional echocardiography accurately assesses the anatomy of the ventricular septal defect, provides additional information, and can be considered a valuable preoperative diagnostic tool.

Secundum atrial septal defect is a dynamic three-dimensional entity.

Background: The aim of this study was to evaluate the diagnostic relevance of 3-dimensional (3D) echocardiography in the assessment of secundum atrial septum defect (ASD2).

Methods And Results: Twenty-three patients (age 2 to 58 years) with an ASD2 were studied by transthoracic (n = 9) or transesophageal (n = 14) echocardiography for the acquisition of a 3D data set before undergoing surgical repair. Qualitative (location, shape, and structure) and quantitative (largest and smallest anteroposterior and superoinferior diameters) characteristics were analyzed and compared with surgical findings.

Use of three-dimensional echocardiography for analysis of outflow obstruction in congenital heart disease.

To evaluate the feasibility and accuracy of 3-dimensional (3D) echocardiography in analysis of left and right ventricular outflow tract (LVOT and RVOT) obstruction, 3D echocardiography was performed in 28 patients (age 4 months to 36 years) with outflow tract pathology. Type of lesion and relation to valves were assessed. Length and degree of obstruction were measured.

Clinical outcome and left ventricular function after pulmonary autograft implantation in children.

Background: Aortic root replacement with a pulmonary autograft is an alternative treatment for children with aortic valve or root disease, or both.

Methods: Twenty-six patients (18 boys and 8 girls) with a mean age of 10.9 years (range, 0.

Allograft root on closed pulmonary valve for subaortic obstruction in double-inlet left ventricle with transposition of the great arteries.

Background: Until recently closure of the pulmonary valve during staged Fontan-type palliation in the setting of double-inlet left ventricle with an unrestrictive or adequately enlarged ventricular septal defect and transposition of the great arteries with the aorta on a left-sided outflow chamber was regarded as an appropriate part of surgical treatment. Lately, however, an increased incidence of subsequent subaortic obstruction has been described in this regard.

Methods: Allograft root placement on the previously closed pulmonary orifice in combination with a modified Damus-Kaye-Stansel procedure is described to create an unobstructed outflow from the main ventricle to the systemic circulation.

Repair of aortic arch interruption by direct anastomosis.

Objective: Evaluation of surgical treatment of interrupted aortic arch (IAA) by direct anastomosis.

Methods: A consecutive series of 17 infants with IAA (type A in eight patients, type B in nine) were operated upon. The mean age at arch repair was 1.

Pediatric Transesophageal Echocardiography by Means of a Miniature 5-MHz Multiplane Transducer.

The development of a miniature multiplane transesophageal echocardiographic (TEE) transducer for pediatric use is the latest development in TEE. Horizontal, longitudinal, and all possible intermediate oblique planes can be obtained with minimal transducer manipulation. We studied 48 patients with an experimental 5-MHz transducer, which contains 48 transmitting elements.

In utero diagnosis of infra-diaphragmatic total anomalous pulmonary venous return.

This report describes the diagnosis of infra-diaphragmatic total anomalous pulmonary venous return in a fetus at 25 weeks of gestation. Abnormal venous pathways were visualized with real-time, pulsed and color Doppler ultrasound. The growth of cardiac structures, especially the left ventricle, was evaluated during subsequent ultrasound examinations.

Two decades of transesophageal phased array probes.

After its introduction about two decades ago, transesophageal echocardiography (TEE) has rapidly evolved into an important diagnostic feature for the cardiologist, since it offers anatomic and hemodynamic information which cannot be obtained precordially. Part of this success was due to the developments in transducer technology which resulted in smaller probes with progressively better imaging qualities. A short review of past, recent and future developments of TEE phased array probes, in particular those at the Erasmus University in Rotterdam, will be given.

Allograft reconstruction of the right ventricular outflow tract.

Objective: Evaluation of allograft reconstruction of the right ventricular outflow tract (RVOT).

Methods: From 1986 to April 1995, 201 allografts (146 pulmonary, 55 aortic) were implanted in 189 patients for conduit reconstruction of the RVOT in congenital heart disease or in the pulmonary autograft procedure. The mean age at allograft implantation was 16 years (range 2 weeks - 54 years).

Decision making for the surgical management of aortic coarctation associated with ventricular septal defect.

Coarctation of the aorta and associated ventricular septal defect may be repaired simultaneously or by initial coarctation repair with or without banding of the pulmonary artery. The question is whether specific preoperative criteria can enable the surgeon to choose the optimal surgical management. Between 1980 and 1993, 80 infants younger than 3 months with coarctation and ventricular septal defect were treated surgically.

Evaluation of the pulmonary vasculature and dynamics with intravascular ultrasound imaging in children and infants.

The ability to assess the pulmonary vasculature in pulmonary vascular disease by hemodynamic or histologic evaluation is limited. We sought to determine the feasibility of intravascular ultrasound techniques in infants and children and to assess simultaneously the morphology and dynamics of pulmonary arteries. Patients were seen in the Department of Pediatrics, Division of Pediatric Cardiology, Sophia Children's Hospital, Rotterdam, The Netherlands.