title: Feasibility and Reproducibility of Echocardiographic Measures in Children with Muscular Dystrophies.
abstract: BACKGROUND
  Cardiac disease is a major cause of death in patients with muscular dystrophies. The use of feasible and reproducible echocardiographic measures of cardiac function is critical to advance the field of therapeutics for dystrophic cardiomyopathy.
  
  
  METHODS
  Participants aged 8 to 18 years with genetically confirmed Duchenne muscular dystrophy (DMD), Becker muscular dystrophy, or limb-girdle muscular dystrophy were enrolled at five centers, and standardized echocardiographic examinations were performed. Measures of systolic and diastolic function and speckle-tracking echocardiography-derived cardiac strain were reviewed independently by two central readers. Furthermore, echocardiographic measures from participants with DMD were compared with those from retrospective age-matched control subjects from a single site to assess measures of myocardial function.
  
  
  RESULTS
  Forty-eight participants (mean age, 13.3 ± 2.7 years) were enrolled. Shortening fraction had a greater interobserver correlation (intraclass correlation coefficient [ICC] = 0.63) compared with ejection fraction (ICC = 0.49). One reader could measure ejection fraction in only 53% of participants. Myocardial performance index measured by pulse-wave Doppler and Doppler tissue imaging showed similar ICCs (0.55 and 0.54). Speckle-tracking echocardiography showed a high ICC (0.96). Focusing on participants with DMD (n = 33), significantly increased mitral A-wave velocities, lower E/A ratios, and lower Doppler tissue imaging mitral lateral E' velocities were observed compared with age-matched control subjects. Speckle-tracking echocardiography demonstrated subclinical myocardial dysfunction with decreased average circumferential and longitudinal strain in three distinct subgroups: participants with DMD with normal shortening fractions, participants with DMD aged < 13 years, and participants with DMD with myocardial performance index scores < 0.40 compared with control subjects.
  
  
  CONCLUSIONS
  In a muscular dystrophy cohort, assessment of cardiac function is feasible and reproducible using shortening fraction, diastolic measures, and myocardial performance index. Cardiac strain measures identified early myocardial disease in patients with DMD.
authors.affiliation: Children's National Health System, Washington, District of Columbia. Electronic address: cspurney@cnmc.org.
authors.forename: Christopher F
authors.initials: CF
authors.lastname: Spurney
authors.affiliation: Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania.
authors.forename: Francis M
authors.initials: FM
authors.lastname: McCaffrey
authors.affiliation: Children's National Health System, Washington, District of Columbia.
authors.forename: Avital
authors.initials: A
authors.lastname: Cnaan
authors.affiliation: Children's National Health System, Washington, District of Columbia.
authors.forename: Lauren P
authors.initials: LP
authors.lastname: Morgenroth
authors.affiliation: Children's National Health System, Washington, District of Columbia.
authors.forename: Sunil J
authors.initials: SJ
authors.lastname: Ghelani
authors.affiliation: Children's National Health System, Washington, District of Columbia.
authors.forename: Heather
authors.initials: H
authors.lastname: Gordish-Dressman
authors.affiliation: Children's National Health System, Washington, District of Columbia.
authors.forename: Adrienne
authors.initials: A
authors.lastname: Arrieta
authors.affiliation: Washington University, St. Louis, Missouri.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Connolly
authors.affiliation: Texas Children's Hospital, Houston, Texas.
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Lotze
authors.affiliation: University of California, Davis, Sacramento, California.
authors.forename: Craig M
authors.initials: CM
authors.lastname: McDonald
authors.affiliation: Children's National Health System, Washington, District of Columbia; University of California, San Diego, San Diego, California.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Leshner
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Veterans Affairs Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Paula R
authors.initials: PR
authors.lastname: Clemens
mesh_terms: D000293:Adolescent; D000465:Algorithms; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000209:etiology; D002648:Child; D004452:Echocardiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D009136:Muscular Dystrophies / Q000150:complications / Q000000981:diagnostic imaging*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology
keywords: Cardiac strain; Cardiomyopathy; Echocardiography; Muscular dystrophy