title: Insight into normal mitral and tricuspid annular dynamics in pediatrics: a real-time three-dimensional echocardiographic study.
abstract: BACKGROUND
  Although there are animal or adult studies analyzing annular motion of the mitral valve (MV) or tricuspid valve (TV) separately, there are no data analyzing interaction between the MV and TV, or data from the pediatric population.
  
  
  METHODS
  A total of 17 healthy children (age 3-15 years) were enrolled in this study. Using real-time 3-dimensional echocardiography, annular area, perimeter, segmental diameter, and bending angle were obtained and analyzed.
  
  
  RESULTS
  MV area increased during systole, in contrast to TV area, which decreased. TV area demonstrated a greater reduction of lateral diameter during systole. Bending motion became most acute in early diastole, which was greater for the TV.
  
  
  CONCLUSIONS
  MV area change differs from adults, which may be explained by a more compliant myocardium in children. Greater lateral forces on TV prevent it from becoming circular, thus, preserving valve competency. Both valves show a bending motion, which becomes most prominent during isovolumic relaxation continuing into early diastole for the TV, suggesting a relationship with torsional forces within the ventricles.
authors.affiliation: Division of Cardiology, The Hospital for Sick Children, The University of Toronto, Faculty of Medicine, Toronto, Ontario, Canada.
authors.forename: Masaki
authors.initials: M
authors.lastname: Nii
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Roman
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Macgowan
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Smallhorn
mesh_terms: D000293:Adolescent; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008943:Mitral Valve / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D019047:Phantoms, Imaging; D013599:Systole / Q000502:physiology*; D014261:Tricuspid Valve / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*