title: Variability of M-mode versus two-dimensional echocardiography measurements in children with dilated cardiomyopathy.
abstract: M-mode and 2-dimensional (2D) echocardiographic imaging are routinely used to quantify left-ventricular (LV) size and function in pediatric patients with dilated cardiomyopathy (DCM). The reproducibility of and correlation between these techniques are unknown. This analysis sought to compare interreader, intrareader, and interacquisition reproducibility of M-mode versus 2D measurements in pediatric DCM patients. The Ventricular Volume Variability study of the Pediatric Heart Network is a multicenter, prospective, observational study assessing the course of chronic DCM in children. Two sonographers performed baseline image acquisitions locally, and two readers performed measurements at the echocardiographic core laboratory. One reader repeated measurements 1 month later. These data were used to assess reproducibility and agreement between M-mode and 2D measurements. One hundred sixty-nine subjects were enrolled. M-mode had similar or greater reproducibility in both intrareader and interreader settings for LV dimensions, shortening fraction (SF), and most wall thicknesses. In contrast, 2D reproducibility was similar or better for nearly all variables in the interacquisition setting but not for SF. Interacquisition variability was approximately twice the intrareader variability. LV dimensions by either modality consistently had high reproducibility and had the highest agreement between modalities. In pediatric DCM patients, variability of linear echocardiographic assessment could be minimized by relying on a single reader and using a consistent method (M-mode or 2D) for serial measurements, preferably M-mode when SF is the primary variable of interest. Except for LV dimensions, M-mode and 2D values should not be used interchangeably due to poor agreement.
authors.affiliation: Washington University in St. Louis, St. Louis, MO, USA, lee_c@kids.wustl.edu.
authors.forename: Caroline K
authors.initials: CK
authors.lastname: Lee
authors.forename: Renee
authors.initials: R
authors.lastname: Margossian
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Sleeper
authors.forename: Charles E
authors.initials: CE
authors.lastname: Canter
authors.forename: Shan
authors.initials: S
authors.lastname: Chen
authors.forename: Lloyd Y
authors.initials: LY
authors.lastname: Tani
authors.forename: Girish
authors.initials: G
authors.lastname: Shirali
authors.forename: Anita
authors.initials: A
authors.lastname: Szwast
authors.forename: Elif Seda Selamet
authors.initials: ES
authors.lastname: Tierney
authors.forename: M Jay
authors.initials: MJ
authors.lastname: Campbell
authors.forename: Fraser
authors.initials: F
authors.lastname: Golding
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wang
authors.forename: Karen
authors.initials: K
authors.lastname: Altmann
authors.forename: Steven D
authors.initials: SD
authors.lastname: Colan
mesh_terms: D000293:Adolescent; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D008297:Male; D012372:ROC Curve; D015203:Reproducibility of Results; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult