Longitudinal evaluation of myocardial function in preterm infants with respiratory distress syndrome.

Aim: Preterm births and respiratory distress syndrome (RDS) are associated with pulmonary vascular disease and altered myocardial function. We serially assessed up to 1 year of age the effects of RDS on global and regional myocardial function of preterm infants, compared to preterm and term controls using conventional echocardiography parameters, tissue Doppler velocities and deformation analysis.

Methods And Results: A total of 120 infants (30 preterm [PT] with RDS, 30 PT controls without RDS, and 60 term controls) underwent conventional and tissue Doppler echocardiography within 72 hours of birth, at corrected term age for the preterm infants, at 1 month corrected, and at 1 year corrected age.

Pulmonary arterial response to hypoxia in survivors of chronic lung disease of prematurity.

Background: It is unclear whether increased pulmonary arterial (PA) reactivity to hypoxia observed in preterm infants who develop chronic lung disease of prematurity (CLD) persists into childhood.

Aim: We assessed and compared PA pulse wave velocity (PWV) in air and after 12% hypoxia using velocity-encoded MRI between children who had CLD in infancy and preterm-born and term-born controls.

Methods: From 67 recruited children, 59 (13 CLD, 21 preterm, 25 term), 9-12-year-old children successfully completed the study.

Long term cardiovascular consequences of chronic lung disease of prematurity.

Pulmonary arterial (PA) hypertension in preterm infant is an important consequence of chronic lung disease of prematurity (CLD) arising mainly due to impaired alveolar development and dysregulated angiogenesis of the pulmonary circulation. Although PA pressure and resistance in these children normalise by school age, their pulmonary vasculature remains hyper-reactive to hypoxia until early childhood. Furthermore, there is evidence that systemic blood pressure in preterm born children with or without CLD is mildly increased at school age and in young adulthood when compared to term-born children.

Assessment of pulmonary artery pulse wave velocity in children: an MRI pilot study.

Purpose: To assess the feasibility of measuring pulmonary artery (PA) pulse wave velocity (PWV) in children breathing ambient air and 12% oxygen.

Methods: Velocity-encoded phase-contrast MR images of the PA were acquired in 15 children, aged 9-12years, without evidence of cardiac or pulmonary diseases. PWV was derived as the ratio of flow to area changes during early systole.

Optimization of myocardial deformation imaging in term and preterm infants.

Aims: Myocardial deformation imaging is now used to assess regional ventricular function in infants but their small size presents particular technical challenges. We therefore investigated the determinants of reproducibility of myocardial longitudinal strain (ε) in term and preterm infants, in order to determine optimal technical settings.

Methods And Results: Repeated longitudinal ε measurements of the mid-segments of the septum, and the left and right ventricular free walls, were performed using five different computation distances (CDs; also called strain length) in 20 infants.