title: Longitudinal Changes and Interobserver Variability of Systolic Myocardial Deformation Values in a Prospective Cohort of Healthy Fetuses across Gestation and after Delivery.
abstract: BACKGROUND
  Normative data for fetal myocardial deformation values have not been comprehensively described in a longitudinal cohort. The effect of gestational age on these values and on interobserver variability require further investigation.
  
  
  METHODS
  Sixty gravid women were prospectively enrolled before 20 weeks' gestation. The following measures were obtained by two blinded observers at five time points across gestation and also at 4 to 8 weeks' postnatal age: global circumferential strain and strain rate, global longitudinal left ventricular strain and strain rate, global longitudinal right ventricular strain and strain rate, and left and right ventricular myocardial performance indices. Optimal myocardial visualization and frame rate (≥100 frames/sec) were ensured.
  
  
  RESULTS
  For gestational age groups ≥24 weeks, intraclass correlation coefficients between observers were >0.70 for all measures and >0.85 for the majority of measures of myocardial deformation. At 20 to 21 weeks' gestation, intraclass correlation coefficients were 0.35 to 0.52 for longitudinal measures and 0.74 to 0.82 for circumferential measures. Myocardial performance index intraclass correlation coefficients were <0.80 at all time points and <0.70 for most time points. Global longitudinal left ventricular strain and global circumferential strain values remained stable across gestational age groups. Global longitudinal right ventricular strain values remained stable across gestation and increased after birth. Global circumferential strain rate, global longitudinal left ventricular strain rate, and global longitudinal right ventricular strain rate decreased from 20 to 21 weeks' gestation to the remainder of gestation and then remained stable until delivery. Upon delivery, global circumferential strain rate and global longitudinal left ventricular strain rate decreased, and global longitudinal right ventricular strain rate increased.
  
  
  CONCLUSIONS
  Interobserver variability of fetal strain and strain rate measured at ≥24 weeks' gestation was lower in comparison with values obtained at 20 to 21 weeks' gestation and lower in comparison with left ventricular and right ventricular myocardial performance indices using the described protocol. Gestational changes in fetal myocardial deformation values likely reflect changes in preload and/or afterload on the fetal heart.
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: samaskat@bcm.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: D000328:Adult; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging* / Q000502:physiology; D005500:Follow-Up Studies; D005865:Gestational Age; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium; D011247:Pregnancy; D011446:Prospective Studies; D012372:ROC Curve; D012016:Reference Values; D015203:Reproducibility of Results; D013599:Systole; D013997:Time Factors; D016216:Ultrasonography, Prenatal / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*
keywords: Cardiac function; Fetal echocardiography; Myocardial deformation; Myocardial performance index; Normative values; Pediatric; Strain; Strain rate