title: Can echocardiography and ECG discriminate hereditary transthyretin V30M amyloidosis from hypertrophic cardiomyopathy?
abstract: OBJECTIVE
  Hereditary transthyretin (ATTR) amyloidosis with increased left ventricular wall thickness could easily be misdiagnosed by echocardiography as hypertrophic cardiomyopathy (HCM). Our aim was to create a diagnostic tool based on echocardiography and ECG that could optimise identification of ATTR amyloidosis.
  
  
  METHODS
  Data were analysed from 33 patients with biopsy proven ATTR amyloidosis and 30 patients with diagnosed HCM. Conventional features from ECG were acquired as well as two dimensional and Doppler echocardiography, speckle tracking derived strain and tissue characterisation analysis. Classification trees were used to select the most important variables for differentiation between ATTR amyloidosis and HCM.
  
  
  RESULTS
  The best classification was obtained using both ECG and echocardiographic features, where a QRS voltage >30 mm was diagnostic for HCM, whereas in patients with QRS voltage <30 mm, an interventricular septal/posterior wall thickness ratio (IVSt/PWt) >1.6 was consistent with HCM and a ratio <1.6 supported the diagnosis of ATTR amyloidosis. This classification presented both high sensitivity (0.939) and specificity (0.833).
  
  
  CONCLUSIONS
  Our study proposes an easily interpretable classification method for the differentiation between HCM and increased left ventricular myocardial thickness due to ATTR amyloidosis. Our combined echocardiographic and ECG model could increase the ability to identify ATTR cardiac amyloidosis in clinical practice.
authors.affiliation: a Division of Clinical Physiology , Heart Centre and Department of Public Health and Clinical Medicine .
authors.forename: Sandra
authors.initials: S
authors.lastname: Gustavsson
authors.forename: Gabriel
authors.initials: G
authors.lastname: Granåsen
authors.forename: Christer
authors.initials: C
authors.lastname: Grönlund
authors.forename: Urban
authors.initials: U
authors.lastname: Wiklund
authors.forename: Stellan
authors.initials: S
authors.lastname: Mörner
authors.forename: Michael
authors.initials: M
authors.lastname: Henein
authors.forename: Ole B
authors.initials: OB
authors.lastname: Suhr
authors.forename: Per
authors.initials: P
authors.lastname: Lindqvist
mesh_terms: D000328:Adult; D000368:Aged; D019943:Amino Acid Substitution; D000686:Amyloidosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology; D001706:Biopsy; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology; D003937:Diagnosis, Differential; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D015870:Gene Expression; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D011228:Prealbumin / Q000235:genetics* / Q000378:metabolism
chemical_list: D011228:Prealbumin
keywords: Cardiac amyloidosis; classification tree; echocardiography; electrocardiography; hypertrophic cardiomyopathy; hypertrophy