title: Speckle Tracking and Transthyretin Amyloid Cardiomyopathy.
abstract: BACKGROUND
  Amyloidosis is a disease caused by deposits of insoluble fibrils in extracellular spaces. The most common type of familial amyloidosis is mediated by mutation of transthyretin, especially Val30Met. Symptoms and ejection fraction decrease may occur in cardiac amyloidosis only in case of poor prognosis. Myocardial strain detected by two-dimensional speckle tracking echocardiography can indicate changes in myocardial function at early stages of the disease.
  
  
  OBJECTIVE
  To determine the accuracy of left ventricular longitudinal strain by two-dimensional speckle tracking echocardiography in patients with familial amyloidosis caused by Val30Met transthyretin mutation.
  
  
  METHODS
  Eighteen consecutive patients, carriers of transthyretin mutation, were evaluated by two-dimensional speckle tracking echocardiography, by which myocardial strain curves were obtained, following the American Society of Echocardiography recommendations.
  
  
  RESULTS
  Patients were divided into three groups: 1- Val30Met with cardiac amyloidosis; 2-Val30Met with extracardiac amyloidosis; 3 - Val30Met without evidence of disease. As the three groups were compared by the Mann-Whitney test, we found a statistically significant difference between groups 1 and 2 in the mean longitudinal tension (p=0.01), mean basal longitudinal strain (p=0.014); in mean longitudinal tension and mean longitudinal strain between groups 1 and 3 (p=0.005); and in the ratio of longitudinal strain of apical septum segment to longitudinal strain of basal septum (p=0.041) between groups 2 and 3.
  
  
  CONCLUSIONS
  Left ventricular longitudinal strain detected by two-dimensional speckle tracking echocardiography is able to diagnose left ventricular dysfunction in early stages of familial amyloidosis caused by transthyretin Val30Met mutation.
authors.affiliation: Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Alexandre Marins
authors.initials: AM
authors.lastname: Rocha
authors.affiliation: Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Suzane Garcia
authors.initials: SG
authors.lastname: Ferreira
authors.affiliation: Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Marcelo Souto
authors.initials: MS
authors.lastname: Nacif
authors.affiliation: Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Mario Luiz
authors.initials: ML
authors.lastname: Ribeiro
authors.affiliation: Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Marcos Raimundo Gomes de
authors.initials: MR
authors.lastname: Freitas
authors.affiliation: Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Cláudio Tinoco
authors.initials: CT
authors.lastname: Mesquita
mesh_terms: D000328:Adult; D028227:Amyloid Neuropathies, Familial / Q000000981:diagnostic imaging* / Q000235:genetics / Q000503:physiopathology; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004452:Echocardiography / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D011228:Prealbumin / Q000235:genetics; D012016:Reference Values; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology
chemical_list: D011228:Prealbumin