title: Noninvasive measurements of hemodynamic transition directly after birth.
abstract: BACKGROUND
  Cardiac output depends on stroke volume and heart rate (HR). Only HR is used to monitor hemodynamic transition.
  
  
  METHODS
  In 24 term newborns born via cesarean section, HR and preductal blood pressure (BP) were measured. Also, using echocardiography, left ventricular dimensions and (Doppler derived) left ventricular output (LVO) were examined at 2, 5, and 10 min after birth.
  
  
  RESULTS
  Mean (SD) HR and BP did not change with time (mean HR: 157 (21) bpm at 2 min, 154 (17) bpm at 5 min, and 155 (14) bpm at 10 min; mean BP: 51.2 (15.4) mm Hg at 2 min, 50.5 (11.7) mm Hg at 5 min, and 49.6 (9.5) mm Hg at 10 min). Left ventricular end-diastolic diameter increased from 2 to 5 min (14.3 (1.3) vs. 16.3 (1.7) mm; P < 0.001) and stabilized at 10 min (16.7 (1.4) mm). LVO increased between 2 and 5 min (151 (47) vs. 203 (55) ml/kg/min; P < 0.001) and stabilized at 10 min (201 (45) ml/kg/min). LVO increase was associated with rise in left ventricular stroke volume (r = 0.94; P < 0.001), not with rise in HR (r = 0.37; P value not significant).
  
  
  CONCLUSIONS
  Left ventricular dimensions and LVO significantly increased the first 5 min after birth and stabilized at 10 min, whereas BP remained stable. LVO and left ventricular dimension increase are presumably due to increasing left ventricular preload resulting from pulmonary blood flow and ductal shunting increase.
authors.affiliation: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: van Vonderen
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Arno A W
authors.initials: AA
authors.lastname: Roest
authors.affiliation: The Ritchie Centre, Monash Institute for Medical Research, Monash University, Clayton, Victoria, Australia.
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Siew
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Nico A
authors.initials: NA
authors.lastname: Blom
authors.affiliation: Department of Gynecology and Obstetrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Jan M
authors.initials: JM
authors.lastname: van Lith
authors.affiliation: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Frans J
authors.initials: FJ
authors.lastname: Walther
authors.affiliation: The Ritchie Centre, Monash Institute for Medical Research, Monash University, Clayton, Victoria, Australia.
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Hooper
authors.affiliation: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Arjan B
authors.initials: AB
authors.lastname: te Pas
mesh_terms: D015415:Biomarkers; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology*; D004452:Echocardiography; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000254:growth & development; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D015415:Biomarkers