title: The endocardial binary appearance ('binary sign') is an unreliable marker for echocardiographic detection of Fabry disease in patients with left ventricular hypertrophy.
abstract: OBJECTIVE
  The binary sign, a binary appearance of the left ventricular endocardial border, was suggested to be an echocardiographic hallmark in diagnosing Fabry disease, a hereditary, lysosomal storage disorder. The aim of the present study was to examine the reliability of the binary sign as a screening tool to identify patients with Fabry disease.
  
  
  RESULTS
  In total 309 subjects with an interventricular septum (IVS) thickness of ≥12 mm were investigated, of which 14 had a confirmed diagnosis of Fabry disease. Urinary globotriaosylceramide testing was used to rule out Fabry disease in the control group. From all patients echocardiographic images of the apical four-chamber view were analysed offline by a blinded observer. A binary sign was seen in 63 patients (20%), 4 had Fabry disease and 59 belonged to the control group. Although the proportion of binary signs in patients with Fabry disease was higher (29%) compared with the control group (20%) this difference was not statistically significant. The sensitivity and specificity were 28% (95% confidence interval (CI): 12-65%) and 80% (95% CI: 76-85%), respectively. In a logistic regression model adjusted for age, sex and presence of Fabry disease, the occurrence of a binary sign was highly dependent on the IVS thickness (odds ratio: 1.21; 95% CI: 1.1-1.35; P<0.001).
  
  
  CONCLUSIONS
  The endocardial binary appearance is associated with the degree of septal hypertrophy but cannot adequately distinguish between patients with Fabry disease and patients with other causes of left ventricular hypertrophy.
authors.affiliation: Department of Medicine II, Division of Cardiology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria. gerald.mundigler@meduniwien.ac.at
authors.forename: Gerald
authors.initials: G
authors.lastname: Mundigler
authors.forename: Martina
authors.initials: M
authors.lastname: Gaggl
authors.forename: Georg
authors.initials: G
authors.lastname: Heinze
authors.forename: Senta
authors.initials: S
authors.lastname: Graf
authors.forename: Manfred
authors.initials: M
authors.lastname: Zehetgruber
authors.forename: Natalija
authors.initials: N
authors.lastname: Lajic
authors.forename: Till
authors.initials: T
authors.lastname: Voigtländer
authors.forename: Christine
authors.initials: C
authors.lastname: Mannhalter
authors.forename: Raute
authors.initials: R
authors.lastname: Sunder-Plassmann
authors.forename: Eduard
authors.initials: E
authors.lastname: Paschke
authors.forename: Günter
authors.initials: G
authors.lastname: Fauler
authors.forename: Gere
authors.initials: G
authors.lastname: Sunder-Plassmann
mesh_terms: D000328:Adult; D000368:Aged; D004452:Echocardiography; D004699:Endocardium / Q000000981:diagnostic imaging*; D000795:Fabry Disease / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results