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.