title: Dysautonomia and ventricular dysfunction in the indeterminate form of Chagas disease.
abstract: BACKGROUND
  The associations between autonomic function and biventricular function in patients with the indeterminate form of Chagas disease remains to be elucidated.
  
  
  METHODS
  In 42 asymptomatic patients and 19 healthy volunteers, the autonomic function was assessed by time domain indices of heart rate variability (HRV), analyzed for 24 h; the right ventricular function was assessed by fraction area change, right ventricle shortening, and systolic excursion of the tricuspid valve; and the left ventricular function was assessed by ejection fraction and transmitral flow velocities. Data were expressed as mean+/-SD or medians (including the lower quartile and upper quartile). Groups were compared by Student's t or Mann-Whitney U test. Autonomic and ventricular function were correlated by Pearson's or Spearman's correlation coefficient. The level of significance was 5%.
  
  
  RESULTS
  Right and left ventricular systolic function indexes were comparable between groups. Transmitral flow velocities were decreased in the Chagas disease group (p<0.05). The patients presented impaired HRV as indicated by the values of SDNN-day (80 (64-99) ms vs. 98 (78-127) ms; p=0.045), SDNNI-24 h (54 (43-71) vs. 65 (54-105) ms; p=0.027), SDNNI-day (49 (42-64) vs. 67 (48-76) ms; p=0.045), pNN50-day (2.2 (0.7-5)% vs. 10 (3-11)%; p=0.033); and pNN50-24 h (3 (1-7)% vs. 12 (8-19)%; p=0.013). There were no correlations between the left ventricular diastolic indices and autonomic dysfunctional indices (p>0.05).
  
  
  CONCLUSIONS
  Patients with the indeterminate form of Chagas disease have both dysautonomia and left ventricular diastolic dysfunction. However, the right ventricular function is preserved. Importantly, ventricular diastolic dysfunction and dysautonomia are independent phenomena.
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina de Botucatu-Universidade Estadual Paulista, UNESP, Brazil.
authors.forename: Roberta B G
authors.initials: RB
authors.lastname: Molina
authors.forename: Beatriz B
authors.initials: BB
authors.lastname: Matsubara
authors.forename: João C
authors.initials: JC
authors.lastname: Hueb
authors.forename: Silméia Garcia
authors.initials: SG
authors.lastname: Zanati
authors.forename: Domingos A
authors.initials: DA
authors.lastname: Meira
authors.forename: José Luiz
authors.initials: JL
authors.lastname: Cassolato
authors.forename: Sergio A R
authors.initials: SA
authors.lastname: Paiva
authors.forename: Leonardo A M
authors.initials: LA
authors.lastname: Zornoff
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000209:etiology* / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000502:physiology; D014355:Chagas Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D015150:Echocardiography, Doppler; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018754:Ventricular Dysfunction / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology