title: Global longitudinal strain and global circumferential strain by speckle-tracking echocardiography and feature-tracking cardiac magnetic resonance imaging: comparison with left ventricular ejection fraction.
abstract: BACKGROUND
  Left ventricular (LV) ejection fraction (EF) is a routine clinical standard to assess cardiac function. Global longitudinal strain (GLS) and global circumferential strain (GCS) have emerged as important LV functional measures. The objective of this study was to determine the relationships of GLS and GCS by speckle-tracking echocardiography and featuring-tracking cardiac magnetic resonance (CMR) to CMR EF as a standard of reference in the same patients.
  
  
  METHODS
  A total of 73 consecutive patients aged 55 ± 15 years clinically referred for both CMR and echocardiography (EF range, 8%-78%) were studied. Routine steady-state free precession CMR images were prospectively analyzed offline using feature-tracking software for LV GLS, GCS, volumes, and EF. GLS was averaged from three standard longitudinal views and GCS from the mid-LV short-axis plane. Echocardiographic speckle-tracking was used from the similar imaging planes for GLS, GCS, LV volumes, and EF.
  
  
  RESULTS
  Feature-tracking CMR strain was closely correlated with speckle-tracking strain in the same patients: GLS, r = -0.87; GCS, r = -0.92 (P < .0001). End-diastolic and end-systolic volumes and EF by feature-tracking CMR were significantly correlated with standard manual tracing of multiple CMR short-axis images (r = 0.97, r = 0.98, and r = 0.97, P < .0001 for all). GLS and GCS by echocardiography and CMR feature-tracking were closely correlated with standard CMR EF: r = -0.85 and r = -0.95, respectively (P < .001). Global strain measures (in absolute values) were correlated with EF using the formula EF = 3(GLS) + 8% or EF = 2.5(GCS) + 8%.
  
  
  CONCLUSIONS
  GLS and GCS by feature-tracking CMR analysis was a rapid means to obtain myocardial strain similar to speckle-tracking echocardiography. GLS and GCS were closely correlated with CMR EF in this patient series and may play a role in the clinical assessment of LV function.
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Onishi
authors.affiliation: Sundsvall Hospital, Sundsvall and Karolinska Institutet, Stockholm, Sweden.
authors.forename: Samir K
authors.initials: SK
authors.lastname: Saha
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Antonia
authors.initials: A
authors.lastname: Delgado-Montero
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Ludwig
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Tetsuari
authors.initials: T
authors.lastname: Onishi
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Erik B
authors.initials: EB
authors.lastname: Schelbert
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: David
authors.initials: D
authors.lastname: Schwartzman
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania. Electronic address: gorcsanj@upmc.edu.
authors.forename: John
authors.initials: J
authors.lastname: Gorcsan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
keywords: Echocardiography; Ejection fraction; Left ventricular function; Magnetic resonance imaging; Myocardial strain