title: Challenging the complementarity of different metrics of left atrial function: insight from a cardiomyopathy-based study.
abstract: OBJECTIVE
  Left ventricular (LV) strain provides incremental values to LV ejection fraction (LVEF) in predicting outcome. We sought to investigate if similar relationship is observed between left atrial (LA) emptying fraction and LA strain.
  
  
  RESULTS
  In this study, we selected 50 healthy subjects, 50 patients with dilated, 50 hypertrophic, and 50 infiltrative (light-chain (AL) amyloidosis) cardiomyopathy (CMP). Echocardiographic measures included LVEF and LA emptying fraction as well as LV and LA longitudinal strain (LVLS and LALS). After regression analysis, comparison of least square means of LA strain among aetiologies was performed. Intraclass correlation coefficient (ICC) and coefficient of variation (COV) were used in the assessment of variability and reproducibility of LV and LA metrics. The mean LVLS and all LA metrics were impaired in patients with all CMP compared with healthy subjects. In contrast to the moderate relationship between LVEF and LVLS (r = -0.51, P < 0.001), there was a strong linear relationship between LA emptying fraction and LA strain (r = 0.87, P < 0.001). In multiple regression analysis, total LA strain was associated with LVLS (β = -0.48, P < 0.001), lateral E/e' (β = -0.24, P < 0.001), age (β = -0.21, P < 0.001), and heart rate (β = -0.14, P = 0.02). The least square mean of LA strain adjusted for the parameters was not different among aetiologies (ANOVA P = 0.82). The ICC (>0.77) and COV (<13) were acceptable.
  
  
  CONCLUSIONS
  In contrast to LV measures, there is a strong linear relationship between volumetric and longitudinal deformation indices of left atrium irrespective of CMP aetiology. Either LA emptying fraction or LA strain could be used as an important parameter in predictive models.
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Kegan J
authors.initials: KJ
authors.lastname: Moneghetti
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Kalyani
authors.initials: K
authors.lastname: Boralkar
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Myriam
authors.initials: M
authors.lastname: Amsallem
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Mirela
authors.initials: M
authors.lastname: Tuzovic
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: David
authors.initials: D
authors.lastname: Liang
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Yang
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Narayan
authors.affiliation: Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Kuznetsova
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wu
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Ingela
authors.initials: I
authors.lastname: Schnittger
authors.affiliation: Division of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.|Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Francois
authors.initials: F
authors.lastname: Haddad
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D016279:Atrial Function, Left; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012016:Reference Values; D012042:Registries; D012044:Regression Analysis; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*
keywords: left atrial function; left ventricular function; strain imaging