title: Two-dimensional speckle tracking as a non-invasive tool for identification of myocardial fibrosis in Fabry disease.
abstract: OBJECTIVE
  This cross-sectional study aimed to analyse myocardial deformation in patients with Fabry disease (FD) in order to evaluate speckle tracking as a method for non-invasive determination of myocardial fibrosis. Myocardial fibrosis is common in Fabry cardiomyopathy and is associated with disease progression and severe prognosis.
  
  
  RESULTS
  In 101 consecutive Fabry patients (39.8 ± 12.9 years; 42 males), the quantitative measurement of myocardial fibrosis with magnetic resonance imaging was compared with regional myocardial deformation assessed by speckle-tracking imaging. Patients were analysed in relation to per cent of late-enhancement (LE)-positive areas of left-ventricular (LV) mass. Fifty-two patients (51%) displayed LE with a mean volume of 1.2 ± 1.8% of total LV mass. Predominantly basal lateral and posterior segments were affected. Patients with LE had lower global systolic longitudinal strain than those without (LE -14.8 ± 3.5% and -18.9 ± 2.1%, respectively; P < 0.001). Loss of global deformation, quantified by speckle tracking, was predominantly caused by basal posterior (P = 0.049) and lateral (P = 0.005) segments and global systolic strain correlated with the amount of LE (r = 0.543; P < 0.001). Patients with severe LE (>2%, n = 22) showed the lowest deformation values (-5.9 ± 8.4%) in basal postero-lateral segments when compared with those with mild (<2%; n = 30, -7.1 ± 7.5%) or no LE (n = 49, -16.3 ± 3.3%). These changes were accompanied by thinning of the posterior wall and a decrease in diastolic function, whereas ejection fraction and LV end-diastolic diameter were not different. Receiver operating characteristic analysis revealed that the systolic strain of basal postero-lateral segments was the most powerful predictor to distinguish between patients with and without LE (sensitivity = 90%; specificity = 97%, area under the curve = 0.913; P < 0.001).
  
  
  CONCLUSIONS
  Late enhancement is associated with lower longitudinal strain in the fibrotic wall segments. Speckle tracking can be used as a tool for the indirect evaluation of LE in FD.
authors.affiliation: Department of Medicine, Department of Cardiology, University of Würzburg, Oberdürrbacherstrasse 6, Würzburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Krämer
authors.forename: Markus
authors.initials: M
authors.lastname: Niemann
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.forename: Kai
authors.initials: K
authors.lastname: Hu
authors.forename: Wolfram
authors.initials: W
authors.lastname: Machann
authors.forename: Meinrad
authors.initials: M
authors.lastname: Beer
authors.forename: Christoph
authors.initials: C
authors.lastname: Wanner
authors.forename: Georg
authors.initials: G
authors.lastname: Ertl
authors.forename: Frank
authors.initials: F
authors.lastname: Weidemann
mesh_terms: D003430:Cross-Sectional Studies; D004452:Echocardiography / Q000379:methods; D000795:Fabry Disease / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005355:Fibrosis / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000473:pathology / Q000503:physiopathology; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D012372:ROC Curve; D013312:Stress, Physiological; D013599:Systole
keywords: Echocardiography; Fabry disease; Magnetic resonance imaging; Myocardial fibrosis; Speckle tracking