title: Assessment of the evolution of normal fetal diastolic function during mid and late gestation by spectral Doppler tissue echocardiography.
abstract: OBJECTIVE
  To establish gestational age-specific reference values in healthy singleton fetuses, we prospectively assessed the evolution of diastolic longitudinal wall-motion velocities by spectral Doppler tissue imaging.
  
  
  METHODS
  Early (Ea) and late diastolic (Aa) peak Doppler tissue imaging velocities were analyzed in 114 fetuses (age range: 14-42 weeks) at the base of right ventricular free wall, ventricular septum, and left ventricular free wall and compared with early (E) and late (A) diastolic peak Doppler inflow velocities.
  
  
  RESULTS
  A linear increase in Ea, Aa, and Ea/Aa ratio was documented at all sites with advancing gestation. Likewise, the peak E flow velocities of both atrioventricular valves and the tricuspid peak A flow velocity increased. The ratio of peak E/Ea velocities decreased exponentially as a result of a more rapid increase in Ea than E, to reach a stable E/Ea relationship only in the early third trimester.
  
  
  CONCLUSIONS
  There was a strong positive correlation between Ea and Aa velocities and gestational age indicating improved diastolic myocardial lengthening with advancing gestation. Reference charts for Doppler tissue imaging velocities were established that will allow identification of fetal diastolic function abnormalities.
authors.affiliation: Division of Cardiology, The Hospital for Sick Children, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Masaki
authors.initials: M
authors.lastname: Nii
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Roman
authors.forename: John
authors.initials: J
authors.lastname: Kingdom
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Redington
authors.forename: Edgar T
authors.initials: ET
authors.lastname: Jaeggi
mesh_terms: D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000196:embryology; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D016216:Ultrasonography, Prenatal / Q000379:methods*; D016276:Ventricular Function; D016277:Ventricular Function, Left / Q000502:physiology*