title: The myocardial function during and after whole-body therapeutic hypothermia for hypoxic-ischemic encephalopathy, a cohort study.
abstract: BACKGROUND
  Therapeutic hypothermia has become standard treatment for moderate and severe neonatal hypoxic-ischemic encephalopathy (HIE) to reduce cerebral morbidity and mortality. The effect on the heart is incompletely explored.
  
  
  OBJECTIVE
  To assess the myocardial function during and after whole-body therapeutic hypothermia for HIE.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  Forty-four infants with HIE cooled for 72hours were compared with 48 healthy term infants and 20 normothermic infants with HIE.
  
  
  METHODS
  Tissue Doppler deformation indices of myocardial function (peak systolic strain, peak systolic strain-rate, early diastole strain-rate and strain-rate in atrial systole) during (days 1 and 3) and after (day 4) therapeutic hypothermia.
  
  
  RESULTS
  On days one and three all indices in both HIE groups were lower than the corresponding indices in the healthy infants. The two HIE groups had similar indices, except peak systolic strain-rate on days 1 and 3 and strain-rate in atrial systole on day 1. All strain-rate indices improved from day 3 to 4 (after rewarming) in the cooled group and achieved similar values to those in healthy infants on day 3. All indices were higher in the cooling-group after rewarming than in the normothermic infants with HIE on day 3, except early diastolic strain-rate.
  
  
  CONCLUSIONS
  Infants with HIE had similarly impaired myocardial function during days 1-3 whether normothermic or hypothermic. The myocardial function improved significantly at day 4 (after rewarming), approaching the day 3 levels in the healthy neonates.
authors.affiliation: Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway; Department of Paediatrics, Vestfold Hospital Trust, Norway. Electronic address: nestaas@hotmail.com.
authors.forename: Eirik
authors.initials: E
authors.lastname: Nestaas
authors.affiliation: Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway; Department of Neonatal Intensive Care, Oslo University Hospital, Ullevål, Norway.
authors.forename: Janne Helen
authors.initials: JH
authors.lastname: Skranes
authors.affiliation: Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Norway; Department of Cardiology, St. Olavs Hospital, Norway.
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Støylen
authors.affiliation: Department of Paediatrics, Oslo University Hospital, Rikshospitalet, Norway.
authors.forename: Leif
authors.initials: L
authors.lastname: Brunvand
authors.affiliation: Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway; Department of Neonatal Intensive Care, Oslo University Hospital, Ullevål, Norway.
authors.forename: Drude
authors.initials: D
authors.lastname: Fugelseth
mesh_terms: D001034:Apgar Score; D001238:Asphyxia Neonatorum / Q000628:therapy*; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D006321:Heart / Q000502:physiology; D006334:Heart Function Tests; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000401:mortality / Q000628:therapy*; D007231:Infant, Newborn; D008297:Male
keywords: Deformation analysis; Myocardial performance; Neonate; Tissue Doppler