title: Assessment of myocardial performance in preterm infants less than 29 weeks gestation during the transitional period.
abstract: BACKGROUND
  The transitional circulation and its effect on myocardial performance are poorly understood in preterm infants.
  
  
  OBJECTIVE
  We assessed myocardial performance in infants less than 29 weeks gestation in the first 48 h of life using a comprehensive echocardiographic assessment.
  
  
  METHODS
  Infants <29 weeks gestation were prospectively enrolled. Small for gestation, infants on inotropes and/or inhaled nitric oxide and septic infants were excluded. Conventional echocardiography, left ventricular (LV), septal and right ventricular (RV) tissue Doppler imaging (TDI) and tissue Doppler-derived strain and strain rate (SR), tricuspid annular plane systolic excursion (TAPSE) and global RV fractional area change (FAC) were assessed at a median of 10 and 45 h post-delivery.
  
  
  RESULTS
  Fifty-four infants with a median [IQR] gestation and birth weight of 26.5 weeks [25.8-28.0 weeks] and 915 g [758-1142 g] were included. There was no change in shortening or ejection fraction across the two time points. Systolic and diastolic TDI of the LV, septum and RV increased across the two time points (all p values ≤ 0.01). There was an increase in septal peak systolic and early diastolic SR (p=0.002). Septal systolic strain and late diastolic SR did not change. With the exception of RV strain and early diastolic SR, all RV functional parameters including SR, late diastolic SR, TAPSE, and FAC increased across the two time points (all p values<0.01).
  
  
  CONCLUSIONS
  Describing the normal hemodynamic adaptations in stable preterm infants during the transitional period provides the necessary information for the assessment of those parameters in various disease states.
authors.affiliation: Department of Paediatrics, The Rotunda Hospital, Dublin, Ireland.
authors.forename: Adam T
authors.initials: AT
authors.lastname: James
authors.affiliation: Department of Paediatrics, The Rotunda Hospital, Dublin, Ireland.
authors.forename: John D
authors.initials: JD
authors.lastname: Corcoran
authors.affiliation: Department of Paediatrics, Mount Sinai Hospital, Toronto, Canada; Department of Physiology, University of Toronto, Toronto, Canada; Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Canada.
authors.forename: Amish
authors.initials: A
authors.lastname: Jain
authors.affiliation: Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Canada; Department of Neonatology, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: McNamara
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Children, Toronto, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Mertens
authors.affiliation: Department of Cardiology, Our Lady's Children's Hospital Crumlin, Dublin, Ireland.
authors.forename: Orla
authors.initials: O
authors.lastname: Franklin
authors.affiliation: Department of Paediatrics, The Rotunda Hospital, Dublin, Ireland; Department of Paediatrics, Royal College of Surgeons in Ireland, Dublin, Ireland. Electronic address: afif@physicians.ie.
authors.forename: Afif F
authors.initials: AF
authors.lastname: El-Khuffash
mesh_terms: D001724:Birth Weight; D003971:Diastole; D015150:Echocardiography, Doppler; D005865:Gestational Age; D006321:Heart / Q000502:physiology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D015203:Reproducibility of Results; D013599:Systole
keywords: FAC; Preterm infant; Strain; Strain rate; TAPSE; Tissue Doppler imaging; Transitional circulation