title: Relative apical sparing of longitudinal strain using two-dimensional speckle-tracking echocardiography is both sensitive and specific for the diagnosis of cardiac amyloidosis.
abstract: BACKGROUND
  The diagnosis of cardiac amyloidosis (CA) is challenging owing to vague symptomatology and non-specific echocardiographic findings.
  
  
  OBJECTIVE
  To describe regional patterns in longitudinal strain (LS) using two-dimensional speckle-tracking echocardiography in CA and to test the hypothesis that regional differences would help differentiate CA from other causes of increased left ventricular (LV) wall thickness.
  
  
  RESULTS
  55 consecutive patients with CA were compared with 30 control patients with LV hypertrophy (n=15 with hypertrophic cardiomyopathy, n=15 with aortic stenosis). A relative apical LS of 1.0, defined using the equation (average apical LS/(average basal LS + mid-LS)), was sensitive (93%) and specific (82%) in differentiating CA from controls (area under the curve 0.94). In a logistic regression multivariate analysis, relative apical LS was the only parameter predictive of CA (p=0.004).
  
  
  CONCLUSIONS
  CA is characterised by regional variations in LS from base to apex. A relative 'apical sparing' pattern of LS is an easily recognisable, accurate and reproducible method of differentiating CA from other causes of LV hypertrophy.
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA.
authors.forename: Dermot
authors.initials: D
authors.lastname: Phelan
authors.forename: Patrick
authors.initials: P
authors.lastname: Collier
authors.forename: Paaladinesh
authors.initials: P
authors.lastname: Thavendiranathan
authors.forename: Zoran B
authors.initials: ZB
authors.lastname: Popović
authors.forename: Mazen
authors.initials: M
authors.lastname: Hanna
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Plana
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
authors.forename: James D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001696:Biomechanical Phenomena; D001706:Biopsy; D009202:Cardiomyopathies / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015588:Observer Variation; D009820:Ohio; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014463:Ultrasonography; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling