title: Usefulness of a new proposed tissue Doppler imaging global function index in hypertrophic cardiomyopathy.
abstract: BACKGROUND
  A global function index (GFI) derived from tissue Doppler imaging (TDI) has been proposed to improve the diagnosis of hypertrophic cardiomyopathy (HCM). We aimed to evaluate the usefulness of this index in a large selected HCM population.
  
  
  METHODS
  GFI =[E/Ea]/Sa, was calculated at mitral annulus lateral and septal borders in 164 HCM patients and in 40 healthy volunteers. Group comparisons and correlations between GFI and other variables were performed.
  
  
  RESULTS
  Of the 164 patients, 69 (42%) had a peak gradient >30 mmHg in the left ventricle outflow tract (LVOT). GFI (lateral or septal) was not normally distributed. There were differences among controls, obstructive HCM, and nonobstructive HCM (P < 0.0001), but significant overlap of GFI values were observed between groups. GFI was correlated to septal thickness (r = 0.44; P < 0.0001), left atrial diameter (r = 0.52; P < 0.0001), and LVOT gradient (r = 0.58; P < 0.0001).
  
  
  CONCLUSIONS
  In a selected HCM population, GFI was limited by its asymmetrical distribution and significant overlap of values between groups. Further studies are necessary to verify the reliability of GFI in the clinical practice and its position among other tissue Doppler indices.
authors.affiliation: Heart Institute (INCOR), University of São Paulo Medical School, São Paulo, Brazil. aloirqueiroz@cardiol.br
authors.forename: Aloir Q
authors.initials: AQ
authors.lastname: Araujo
authors.forename: Edmundo
authors.initials: E
authors.lastname: Arteaga
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Ianni
authors.forename: Vera Maria C
authors.initials: VM
authors.lastname: Salemi
authors.forename: Felix J A
authors.initials: FJ
authors.lastname: Ramires
authors.forename: Afonso Y
authors.initials: AY
authors.lastname: Matsumoto
authors.forename: Fabio
authors.initials: F
authors.lastname: Fernandes
authors.forename: Charles
authors.initials: C
authors.lastname: Mady
mesh_terms: D000293:Adolescent; D000328:Adult; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018709:Statistics, Nonparametric