title: Indeterminate form of Chagas disease: is left ventricular torsional mechanics a clue to subclinical myocardial abnormalities?
abstract: Chagas disease (CD) is highly endemic in Latin America, and has been emerging in developed countries. Early diagnosis of left ventricular (LV) systolic dysfunction, routinely done by echocardiography, is crucial for therapy. Speckle tracking echocardiography allows determination of LV segmental rotations, twist/torsion, and this analysis may disclose an unapparent myocardial contractile deficit in initial stages of CD. Therefore, this study aimed to highlight a possible unapparent myocardial contractile deficit in CD indeterminate form (IF) by a comprehensive torsional mechanics analysis.
  
  
  
  Patients with CDIF diagnosis, initial chagasic cardiomyopathy (CCMP characterized by ECG abnormalities and LVEF > 0.55), and normal controls were prospectively enrolled, and underwent conventional echocardiogram with images acquisition for STE offline analysis. Target parameters were basal and apical rotations, and calculation of twist and torsion.
  
  
  
  A total of 42 patients were included (CDIF, eight; CCMP, 13; and 21 controls). Chagasic patients had a mean age of 55 years, five (24 %) men, and controls, 50 years, seven (33 %) men. Torsional mechanics analyzes resulted in no significant difference in all parameters studied between groups. Twist in CDIF was 20.8° ± 6.5°; CCMP, 19.0° ± 3.5° and controls, 19.7° ± 3.7° (p = 0.67). Torsion in CDIF was 2.6° ± 0.8°; CCMP, 2.4° ± 0.6° and controls, 2.4° ± 0.5° (p = 0.63).
  
  
  
  Patients with Chagas disease have no abnormalities in torsional mechanics during its indeterminate and initial cardiomyopathy stages.
authors.affiliation: The Heart Institute (InCor), University of Sao Paulo Medical School, Av Dr Eneas de Carvalho Aguiar, 44 Cerqueira Cesar, São Paulo, 05.403-000, Brazil. marcio.lima@incor.usp.br.
authors.forename: Marcio Silva Miguel
authors.initials: MS
authors.lastname: Lima
authors.affiliation: The Heart Institute (InCor), University of Sao Paulo Medical School, Av Dr Eneas de Carvalho Aguiar, 44 Cerqueira Cesar, São Paulo, 05.403-000, Brazil.
authors.forename: Mariana Callil
authors.initials: MC
authors.lastname: Voos
authors.affiliation: The Heart Institute (InCor), University of Sao Paulo Medical School, Av Dr Eneas de Carvalho Aguiar, 44 Cerqueira Cesar, São Paulo, 05.403-000, Brazil.
authors.forename: Wilson
authors.initials: W
authors.lastname: Mathias
authors.affiliation: The Heart Institute (InCor), University of Sao Paulo Medical School, Av Dr Eneas de Carvalho Aguiar, 44 Cerqueira Cesar, São Paulo, 05.403-000, Brazil.
authors.forename: Jeane Mike
authors.initials: JM
authors.lastname: Tsutsui
mesh_terms: D002598:Chagas Cardiomyopathy / Q000175:diagnosis* / Q000000981:diagnostic imaging; D017548:Echocardiography, Transesophageal / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: Chagas disease; Speckle tracking; Torsion; Twist