title: New two-dimensional global longitudinal strain and strain rate imaging for assessment of systemic right ventricular function.
abstract: OBJECTIVE
  To determine the usefulness of new two-dimensional strain indices, based on speckle tracking imaging, for assessment of systemic right ventricular (RV) function after an atrial switch operation for transposition of the great arteries.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Tertiary paediatric cardiac centre.
  
  
  METHODS
  26 patients, mean (SD) age 21.0 (3.6) years at 19.9 (3.2) years after an atrial switch operation, and 27 age-matched controls were studied. Two-dimensional imaging at the four-chamber view was obtained with tracing of the entire RV endocardial border. The RV global longitudinal strain (GLS) and GLS rate were derived using automated software (EchoPAC, GE Medical) and correlated with tissue Doppler-derived RV isovolumic acceleration (IVA), and, in the patient cohort, with cardiac magnetic resonance-derived RV ejection fraction.
  
  
  RESULTS
  Intra- and interobserver variability for measurement of GLS, as determined from the mean (SD) of differences in two consecutive results from 20 studies, were 0.06 (1.39)% and 0.24 (1.77)%, respectively. Compared with controls, patients had lower RV GLS (17.1 (1.9)% vs 26.3 (2.9)%, p<0.001), a reduced GLS rate (0.78 (0.11)/s vs 1.33 (0.23)/s, p<0.001), lower RV IVA (1.10 (0.36) m/s(2) vs 1.56 (0.53) m/s(2), p<0.001) and increased RV myocardial performance index (0.52 (0.09) vs 0.38 (0.09), p<0.001). Both RV GLS and GLS rate correlated positively with RV IVA (r = 0.43, p = 0.001 and r = 0.46, p<0.001, respectively), and negatively with RV myocardial performance index (r = -0.65, p<0.001 and r = -0.57, p<0.001, respectively). In patients, the GLS rate correlated positively with RV ejection fraction (r = 0.62, p = 0.001).
  
  
  CONCLUSIONS
  Two-dimensional RV GLS and GLS rate are new, potentially useful indices for assessment of systemic RV function.
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Division of Paediatric Cardiology, Grantham Hospital, The University of Hong Kong, 125 Wong Chuk Hang Road, Hong Kong, China.
authors.forename: P-C
authors.initials: PC
authors.lastname: Chow
authors.forename: X-C
authors.initials: XC
authors.lastname: Liang
authors.forename: E W Y
authors.initials: EW
authors.lastname: Cheung
authors.forename: W W M
authors.initials: WW
authors.lastname: Lam
authors.forename: Y-F
authors.initials: YF
authors.lastname: Cheung
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D018618:Echocardiography, Doppler, Color / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008134:Long-Term Care / Q000379:methods; D009200:Myocardial Contraction; D015588:Observer Variation; D011184:Postoperative Period; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013318:Stroke Volume; D014188:Transposition of Great Vessels / Q000601:surgery*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016278:Ventricular Function, Right