title: Quantification of regional left and right ventricular deformation indices in healthy neonates by using strain rate and strain imaging.
abstract: BACKGROUND
  Color Doppler myocardial imaging (CDMI) allows the calculation of local longitudinal or radial strain rate (SR) and strain (epsilon). The aims of this study were to determine the feasibility and reproducibility of longitudinal and radial SR and epsilon in neonates during the first hours of life and to establish reference values.
  
  
  METHODS
  Data were obtained from 55 healthy neonates (29 male; mean age, 20 +/- 14 hours; mean birth weight, 3,174 +/- 374 g). Apical and parasternal views quantified regional longitudinal and radial SR and epsilon in differing ventricular wall segments. Values at peak systole, early diastole, and late diastole were calculated from the extracted curves. CDMI data acquired at 300 +/- 50 frames/s were analyzed offline. Three consecutive cardiac cycles were measured during normal respiration. The timing of specific systolic or diastolic regional events was determined. Multiple comparisons between walls and segments were made.
  
  
  RESULTS
  Left ventricular (LV) longitudinal deformation showed basal differences compared with apical segments within one specific wall. Right ventricular (RV) longitudinal deformation was not homogeneous, with significant differences between basal and apical segments. Longitudinal epsilon values were higher in the RV free basal and middle wall segments compared with the left ventricle. In the RV free wall apical segment, longitudinal SR and epsilon were maximal. LV systolic SR and epsilon values were higher radially compared with longitudinally (radial peak systolic SR midportion, 2.9 +/- 0.6 s(-1); radial peak systolic epsilon, 53.8 +/- 19%; longitudinal peak systolic SR midportion, -1.8 +/- 0.5 s(-1); longitudinal peak systolic epsilon, -24.8 +/- 3%; P < .01). Longitudinal systolic epsilon and SR interobserver variability values were 1.2% and 0.7%, respectively.
  
  
  CONCLUSIONS
  Ultrasound-based SR and epsilon imaging is a practical and reproducible clinical technique in neonates, allowing the calculation of regional longitudinal and radial deformation in RV and LV segments. These regional SR and epsilon indices represent new, noninvasive parameters that can quantify normal neonate regional cardiac function. Independent from visual interpretation, they can be used as reference values for diagnosis in ill neonates.
authors.affiliation: Maternidade Hilda Brandão, Santa Casa, Belo Horizonte, Brazil. jlpena.bh@terra.com.br
authors.forename: José Luiz Barros
authors.initials: JL
authors.lastname: Pena
authors.forename: Marconi Gomes
authors.initials: MG
authors.lastname: da Silva
authors.forename: Sanny Cristina Castro
authors.initials: SC
authors.lastname: Faria
authors.forename: Vera Maria Cury
authors.initials: VM
authors.lastname: Salemi
authors.forename: Charles
authors.initials: C
authors.lastname: Mady
authors.forename: Aigul
authors.initials: A
authors.lastname: Baltabaeva
authors.forename: George R
authors.initials: GR
authors.lastname: Sutherland
mesh_terms: D000465:Algorithms; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007231:Infant, Newborn; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical