title: Systolic and diastolic function assessment in fabry disease patients using speckle-tracking imaging and comparison with conventional echocardiographic measurements.
abstract: BACKGROUND
  Fabry cardiomyopathy is characterized by progressive left ventricular hypertrophy (LVH) associated with diastolic dysfunction and is the most common cause of death in Fabry disease (FD). However, LVH is not present in all subjects, particularly early in disease progression and in female patients. Direct assessment of myocardial deformation by strain and strain rate (SR) analysis may be sensitive to detect subclinical Fabry cardiomyopathy independent of the presence of LVH.
  
  
  METHODS
  Systolic (longitudinal, circumferential, and radial systolic strain and SR) and diastolic (SR during isovolumic relaxation [SR(IVR)] and early diastole and strain at peak transmitral E wave) function was assessed in 16 patients with FD using two-dimensional speckle-tracking echocardiography. In addition, mean S' and E' mitral annular velocities by Doppler tissue imaging were measured. Diastolic filling indices, including E/SR(IVR) and E/E' ratios, were calculated. The patients were compared with 24 healthy age-matched and gender-matched controls.
  
  
  RESULTS
  All 16 patients with FD had normal left ventricular ejection fractions, and nine patients had LVH. Compared with controls, patients with FD had reduced longitudinal systolic strain (P < .001) and systolic SR (P = .007), while there were no differences in circumferential systolic strain and S'. Diastolic function assessment showed reduced longitudinal early diastolic SR (P = .001), SR(IVR) (P < .001), and E/SR(IVR) (P < .001), while radial and circumferential diastolic function was not affected. Of the conventional diastolic function indices, reductions were seen in E (P = .006), E' (P = .021), and E/E' ratio (P < .001). After correcting for LVH, only SR(IVR) (P < .001) and E/SR(IVR) (P = .025) remained significantly different between patients with FD and controls, with sensitivity of 94% and specificity of 92% for SR(IVR) of 0.235 sec(-1) (area under the receiver operating characteristic curve, 0.953).
  
  
  CONCLUSIONS
  Strain and SR analysis is useful in identifying patients with FD with reduced myocardial function, with longitudinal systolic strain and diastolic isovolumic SR being superior to the other echocardiographic measurements of myocardial contraction and relaxation and independent of LVH.
authors.affiliation: Division of Cardiology, Department of Medicine, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Miriam
authors.initials: M
authors.lastname: Shanks
authors.forename: Richard B
authors.initials: RB
authors.lastname: Thompson
authors.forename: Ian D
authors.initials: ID
authors.lastname: Paterson
authors.forename: Brendan
authors.initials: B
authors.lastname: Putko
authors.forename: Aneal
authors.initials: A
authors.lastname: Khan
authors.forename: Alicia
authors.initials: A
authors.lastname: Chan
authors.forename: Harald
authors.initials: H
authors.lastname: Becher
authors.forename: Gavin Y
authors.initials: GY
authors.lastname: Oudit
mesh_terms: D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D000795:Fabry Disease / Q000150:complications* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology*
keywords: 2D; DTI; Diastolic function; Doppler tissue imaging; Early diastolic strain rate; Echocardiography; FD; Fabry disease; LV; LVH; Left ventricular; Left ventricular hypertrophy; Myocardial function; ROC; Receiver operating characteristic; SR; SR(E); SR(IVR); SR(S); Speckle-tracking; Strain; Strain rate; Strain rate during the isovolumic relaxation period; Systolic strain; Systolic strain rate; Two-dimensional; ε