title: Reference ranges for cardiac dimensions and blood flow velocity in preterm infants.
abstract: OBJECTIVE
  To establish reference ranges for cardiac dimensions and Doppler measurements in preterm infants.
  
  
  METHODS
  79 infants of less than 34 weeks' gestation were examined by echocardiography on days 0, 7, and 28 after birth, to produce a set of reference ranges and to examine changes in these indices over the first month of life. The following dimensions were measured: interventricular septum, left ventricular posterior wall, left interventricular diameter at end systole and diastole, left atrium, and aortic root; Doppler measurements were made of maximum blood flow velocity (Vmax) through the pulmonary, aortic, mitral, and tricuspid valves.
  
  
  RESULTS
  Reference ranges are given. Cardiac dimensions correlated well with gestation and birth weight but Vmax did not. There was a significant increase in measurements over time. The "normal" preterm infant also appeared to often have asymmetrical septal hypertrophy. Antenatal dexamethasone administration did not appear to affect the measurements.
  
  
  CONCLUSIONS
  There is a close correlation with both gestation and birth weight for all physical measurements. Echocardiograms in preterm babies clearly differ from those in older children and adults.
authors.affiliation: Peter Congden Neonatal Intensive Care Unit, Leeds General Infirmary, UK.
authors.forename: R
authors.initials: R
authors.lastname: Skelton
authors.forename: A B
authors.initials: AB
authors.lastname: Gill
authors.forename: J M
authors.initials: JM
authors.lastname: Parsons
mesh_terms: D001783:Blood Flow Velocity; D003326:Coronary Circulation / Q000502:physiology; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D012016:Reference Values