title: Fetal and Neonatal Diastolic Myocardial Strain Rate: Normal Reference Ranges and Reproducibility in a Prospective, Longitudinal Cohort of Pregnancies.
abstract: Normative fetal diastolic strain rate values have not been comprehensively reported. The aims of this study were to report normative data for diastolic strain rate parameters across gestation and upon delivery, determine the effect of advancing gestational age on these measures, and compare interobserver variability at multiple gestational age time points.
  
  
  
  Sixty gravid women were enrolled before 20 weeks' gestation. The following measures were obtained by two blinded observers at five time points across gestation and at 4 to 8 weeks' postnatal age: global left ventricular circumferential strain rate peak E and A waves, global left and right ventricular longitudinal strain rate peak E and A waves, and mitral and tricuspid valve E/A ratios. Reproducibility was assessed using intraclass correlation and Bland-Altman analysis. Least square means analysis was used to evaluate for changes across gestational age.
  
  
  
  Left ventricular longitudinal and circumferential diastolic strain rate values decreased across gestation, while right ventricular longitudinal values remained stable. With delivery, left ventricular values remained fairly stable, while right ventricular values increased. Intraclass correlations for diastolic strain rate values were 0.68 to 0.94 at ≥24 weeks' gestation and 0.25 to 0.82 for values at 20 to 21 weeks' gestation. Intraclass correlations ranged from 0.49 to 0.90 for mitral valve and tricuspid valve E/A ratios across gestation.
  
  
  
  Fetal measures of diastolic strain rate have acceptable reproducibility after 24 weeks' gestation. The described changes across gestation likely reflect intrinsic myocardial adaptation to loading conditions. These reference ranges can be used to assess effects of various disease states on fetal myocardial deformation.
authors.affiliation: Texas Children's Fetal Center, Texas Children's Hospital, Houston, Texas; Section of Pediatric Cardiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas. Electronic address: shirazm@stanford.edu.
authors.forename: Shiraz Arif
authors.initials: SA
authors.lastname: Maskatia
authors.affiliation: Texas Children's Fetal Center, Texas Children's Hospital, Houston, Texas; Section of Pediatric Cardiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas.
authors.forename: Ricardo H
authors.initials: RH
authors.lastname: Pignatelli
authors.affiliation: Texas Children's Fetal Center, Texas Children's Hospital, Houston, Texas; Section of Pediatric Cardiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas.
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Ayres
authors.affiliation: Texas Children's Fetal Center, Texas Children's Hospital, Houston, Texas; Section of Pediatric Cardiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Altman
authors.affiliation: Texas Children's Fetal Center, Texas Children's Hospital, Houston, Texas; Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas.
authors.forename: Haleh
authors.initials: H
authors.lastname: Sangi-Haghpeykar
authors.affiliation: Texas Children's Fetal Center, Texas Children's Hospital, Houston, Texas; Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas.
authors.forename: Wesley
authors.initials: W
authors.lastname: Lee
mesh_terms: D000375:Aging / Q000502:physiology; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods / Q000592:standards*; D055119:Elastic Modulus / Q000502:physiology; D005260:Female; D005865:Gestational Age; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000196:embryology*; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D011247:Pregnancy / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013318:Stroke Volume / Q000502:physiology; D013718:Tensile Strength / Q000502:physiology; D013781:Texas; D016216:Ultrasonography, Prenatal / Q000379:methods / Q000592:standards*; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Cardiac function; Diastolic function; Fetal echocardiography; Myocardial deformation; Normative values; Pediatric; Strain rate