title: The diameter of coronary arteries in healthy newborns at birth, 1 and 6 months of ages.
abstract: OBJECTIVE
  The aim of this study was to determine accurate and validated Z-score equations for the normal values of coronary diameters adjusted with growth changes of the neonates by testing three different time periods.
  
  
  METHODS
  Echocardiography was performed on 200 healthy neonates at birth, 1 and 6 months of ages. Several regression models for the left (LCA) and right coronary artery (RCA) diameters were tested with weight, height, body surface area and aortic annulus diameter. Reliable standards for the coronary artery diameters for healthy newborns by determining Z-score equations with appropriate statistical validations were established.
  
  
  RESULTS
  The coronary diameters on birth measurements were strongly correlated with birth weight, height, surface area and the diameter of the aortic annulus (Pearson's R > 0.8, all p < 0.01). There were significant associations between the mean data of weight, height, body surface area, aortic annulus and the LCA and RCA diameters measurements of study subjects at birth, 1 and 6 months of ages (p < 0.05). Z-score graphs of coronary artery diameters and weight of the subjects at three different time (LCA vs. weight at birth, R = 0.82, p < 0.001; LCA vs. weight at 1 month, R = 0.64, p < 0.001; LCA vs. weight at 6 months, R = 0.55, p < 0.001; RCA vs. weight at birth, R = 0.80, p < 0.001; RCA vs. weight at 1 month, R = 0.59, p < 0.001; RCA vs. weight at 6 months, R = 0.49, p < 0.001) were constructed.
  
  
  CONCLUSIONS
  We present a new set of equations for neonatal Z-score calculation on the basis of a large number of healthy neonates on three different time period consisting of birth, 1 and 6 months of ages. It is clear with this study that the growth in caliber of the coronary arteries is definite and progressive during postnatal time.
authors.affiliation: Division of Neonatology, Dr. Sami Ulus Maternity, Childrens' Education and Research Hospital, Ankara, Turkey. belmakaragol@gmail.com
authors.forename: Belma Saygili
authors.initials: BS
authors.lastname: Karagol
authors.forename: Utku Arman
authors.initials: UA
authors.lastname: Orun
authors.forename: Aysegul
authors.initials: A
authors.lastname: Zenciroglu
authors.forename: Selcen Pehlivan
authors.initials: SP
authors.lastname: Yuksel
authors.forename: Nurullah
authors.initials: N
authors.lastname: Okumus
authors.forename: Selmin
authors.initials: S
authors.lastname: Karademir
mesh_terms: D000367:Age Factors; D001724:Birth Weight / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D048429:Cell Size; D002657:Child Development / Q000502:physiology; D015331:Cohort Studies; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000254:growth & development*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006262:Health; D006801:Humans; D007223:Infant; D007231:Infant, Newborn / Q000254:growth & development; D008297:Male; D036801:Parturition / Q000502:physiology; D054928:Validation Studies as Topic