title: Left ventricular myocardial strain by three-dimensional speckle-tracking echocardiography in healthy subjects: reference values and analysis of their physiologic and technical determinants.
abstract: BACKGROUND
  Despite growing interest in applying three-dimensional (3D) speckle-tracking echocardiography (STE) to measure left ventricular (LV) myocardial deformation in various diseases, normative values for 3D speckle-tracking echocardiographic parameters and the effects of demographic, hemodynamic, and technical factors on these values are unknown.
  
  
  METHODS
  In 265 healthy volunteers (age range, 18-76; 57% women), longitudinal strain (3DLε), circumferential strain (3DCε), radial strain (3DRε), and area strain (3DAε) were measured by using vendor-specific (Vsp) 3D speckle-tracking echocardiographic equipment. LV strain was also measured by using Vsp two-dimensional (2D) and vendor-independent 3D speckle-tracking echocardiographic software packages, for comparison.
  
  
  RESULTS
  Reference values (lower limit of normality) for Vsp 3D STE were -17% to -21% (-15%) for 3DLε, -17% to -20% (-14%) for 3DCε, -31% to -36% (-26%) for 3DAε, and 47% to 59% (38%) for 3DRε. Three-dimensional longitudinal strain decreased, whereas 3DCε increased, with aging (P < .003), with different trends in men and women. Men had lower 3DLε, 3DRε, 3DAε, and 2D longitudinal strain than women (P < .02). LV 3D strain parameters were also influenced by LV volumes and mass, image quality, and temporal resolution (P < .02). Reference values obtained by Vsp 2D STE were -20% to -23% (-18%) for 2D longitudinal strain, -20% to -24% (-17%) for 2D circumferential strain, and 39% to 54% (28%) for 2D radial strain (P < .001 vs Vsp 3D STE). Significantly different 3DCε and 3DRε values were obtained with vendor-independent versus Vsp 3D STE (P < .001).
  
  
  CONCLUSIONS
  In healthy subjects, reference values of LV 3D strain parameters were significantly influenced by demographic, cardiac, and technical factors. Limits of normality of LV strain by Vsp 3D STE should not be used interchangeably with Vsp 2D STE or with Vin 3D STE software.
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy. Electronic address: denisa.muraru@gmail.com.
authors: Denisa
authors: D
authors: Muraru
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Umberto
authors: U
authors: Cucchini
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy; University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania.
authors: Sorina
authors: S
authors: Mihăilă
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy; Cardiology Institute of Rio Grande do Sul, Porto Alegre, Brazil.
authors: Marcelo Haertel
authors: MH
authors: Miglioranza
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Patrizia
authors: P
authors: Aruta
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Giacomo
authors: G
authors: Cavalli
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Antonella
authors: A
authors: Cecchetto
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Seena
authors: S
authors: Padayattil-Josè
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Diletta
authors: D
authors: Peluso
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Sabino
authors: S
authors: Iliceto
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy.
authors: Luigi P
authors: LP
authors: Badano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D055119:Elastic Modulus; D005260:Female; D064368:Healthy Volunteers; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
keywords: Deformation; Echocardiography; Healthy subjects; Left ventricle; Normal subjects; Speckle-tracking; Strain; Three-dimensional