title: Mechanical Dispersion Assessed by Strain Echocardiography Is Associated with Malignant Arrhythmias in Chagas Cardiomyopathy.
abstract: BACKGROUND
  Sudden death is one of the characteristics of Chagas disease (ChD). With the development of strategies for the prevention of malignant arrhythmias, especially with implantable cardioverter-defibrillators (ICDs), there is interest in developing strategies to predict sudden cardiac death. The aim of this study was to test the hypothesis that global longitudinal strain (GLS) and mechanical dispersion (MD) may be associated with malignant ventricular arrhythmias in patients with ChD.
  
  
  METHODS
  A cross-sectional study was conducted including 62 patients with ChD who were separated into two groups according to ICD implantation status. Group 0 consisted of 34 patients with ChD without ICDs, and group 1 comprised 28 patients with ICDs. Complete echocardiographic studies, including GLS and MD measurements, were performed in all patients.
  
  
  RESULTS
  Chamber dimensions, ejection fraction, and diastolic function showed no significant differences between patients with and those without ICDs. GLS was reduced in patients with ChD with ICDs compared with those without (P = .02). By receiver operating characteristic curve analyses, GLS identified patients with ChD with ICDs with sensitivity of 67% and specificity of 69%. MD was more pronounced in patients with ChD with ICDs compared with those without (P < .001), with a C statistic of 0.83 (95% CI, 0.71-0.91). MD > 57 msec detected ICD presence with sensitivity of 79% and specificity of 71% and was superior to GLS and ejection fraction (P < .05). In multivariate analysis, New York Heart Association functional class (odds ratio, 3.02; 95% CI, 1.09-8.39; P = .03), MD (odds ratio, 1.11; 95% CI, 1.04-1.19; P = .001), and GLS (odds ratio, 0.72; 95% CI, 0.54-0.96; P = .026) were significant and independently associated with malignant arrhythmic events.
  
  
  CONCLUSIONS
  GLS and MD may add important information in the risk stratification of patients with ChD. The use of MD by strain echocardiography could be an attractive tool in the decision making for ICD placement as primary prevention for sudden cardiac death in patients with ChD.
authors.affiliation: Hospital das Clínicas e Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Mater Dei Hospital, Belo Horizonte, Brazil. Electronic address: marciovlbarros@gmail.com.
authors.forename: Marcio V L
authors.initials: MV
authors.lastname: Barros
authors.affiliation: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Center for Cardiological Innovation and University of Oslo, Oslo, Norway.
authors.forename: Ida S
authors.initials: IS
authors.lastname: Leren
authors.affiliation: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Center for Cardiological Innovation and University of Oslo, Oslo, Norway.
authors.forename: Thor
authors.initials: T
authors.lastname: Edvardsen
authors.affiliation: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Center for Cardiological Innovation and University of Oslo, Oslo, Norway.
authors.forename: Kristina H
authors.initials: KH
authors.lastname: Haugaa
authors.affiliation: Hospital das Clínicas e Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Andre A L
authors.initials: AA
authors.lastname: Carmo
authors.affiliation: Hospital das Clínicas e Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Thais A R
authors.initials: TA
authors.lastname: Lage
authors.affiliation: Hospital das Clínicas e Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Maria Carmo P
authors.initials: MC
authors.lastname: Nunes
authors.affiliation: Hospital das Clínicas e Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Manoel O C
authors.initials: MO
authors.lastname: Rocha
authors.affiliation: Hospital das Clínicas e Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Antonio L P
authors.initials: AL
authors.lastname: Ribeiro
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D002598:Chagas Cardiomyopathy / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004452:Echocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology*
keywords: Chagas disease; Malignant arrhythmias; Strain echocardiography