title: Intraobserver and interobserver reproducibility for radial, circumferential and longitudinal strain echocardiography.
abstract: OBJECTIVE
  Strain echocardiography (StE) promises to be a new tool for quantitative assessment of cardiac function. Analysis of intra- and interobserver reliability is an important aspect in the process of developing these novel techniques from theory to the implementation into daily routine diagnostics.The purpose of the study was to estimate reliability of the segmental StE.
  
  
  METHODS
  Left ventricular strain analysis for radial strain (RS), circumferential strain (CS) and longitudinal strain (LS) was performed in 21 healthy volunteers. RS and CS values were obtained in the parasternal short axis at the level of the papillary muscles. LS values were determined in the apical 2-, 3- and 4-chamber views. Cine-loops were recorded and quantitative analyses were conducted on an off-line workstation.
  
  
  RESULTS
  Intraobserver reproducibility was highest using LS in the 4-chamber view (9 ± 13.6 % mean deviation, rho = 0.624, p = 0.003), followed by CS (13.3 ± 8.3 %, rho = 0.406, p = 0.068) and lowest in RS (26.3 ± 30.1 %, rho = 0.391, p = 0.080). Interobserver analyses of LS derived from 3-chamber view showed lowest deviation (11.9 ± 9.5 %, rho = 0.513, p = 0.017), followed by CS (15.2 ± 12.0 %, 0.263, p = 0.249) and the least consistent measurements in RS (35.9 ± 46.3 %, rho 0.382, p = 0.088).
  
  
  CONCLUSIONS
  This study shows that the clinical utility of StE depends on the regional differences of LV wall motion and image quality. LS-values showed promising intra- and interobserver reproducibility values. For quantitative follow-up studies LS should be preferred.
authors.affiliation: Department of Cardiology, Section Prevention and Sports Medicine, Witten/Herdecke University, Faculty of Health, School of Medicine, Hagen, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Leischik
authors.affiliation: Department of Cardiology, Section Prevention and Sports Medicine, Witten/Herdecke University, Faculty of Health, School of Medicine, Hagen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Dworrak
authors.affiliation: Helios Children Hospital, Witten/Herdecke University, Faculty of Health, School of Medicine, Wuppertal, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Hensel
keywords: Interobserver-varability; intraobserver-variability; reproducibility; strain.