title: Etanercept induces low QRS voltage and autonomic dysfunction in mice with experimental Chagas disease.
abstract: BACKGROUND
  Chagas disease is a tropical parasitic disease caused by the flagellate protozoan Trypanosoma cruzi. Chagasic cardiomyopathy is characterized by disorders of autonomic regulation and action potential conduction in the acute and chronic phases of infection. Although tumor necrosis factor alpha (TNF-α) has been linked to cardiomyopathy in experimental models and in patients with Chagas disease, other reports suggest that TNF-α may exert anti-parasitic actions during the acute phase of infection.
  
  
  OBJECTIVE
  This study aimed to determine the effects of a soluble TNF-α agonist, etanercept, on electrocardiographic parameters in the acute phase of experimental infection with Trypanosoma cruzi.
  
  
  METHODS
  Electrocardiograms were obtained from untreated infected mice and infected mice who were treated with etanercept 7 days after infection. ECG wave and heart rate variability parameters were determined using Chart for Windows.
  
  
  RESULTS
  Etanercept treatment resulted in a low QRS voltage and decreased heart rate variability compared with no treatment. However, the treated mice exhibited a delay in the fall of the survival curve during the acute phase.
  
  
  CONCLUSIONS
  The results of this study suggest that although etanercept treatment promotes survival in mice infected with a virulent T. cruzi strain, TNF-α blockade generates a low voltage complex and autonomic dysfunction during the acute phase of infection. These findings indicate that mortality during the acute phase can be attributed to a systemic inflammatory response rather than cardiac dysfunction.
authors.forename: Héctor
authors.initials: H
authors.lastname: Rodríguez-Angulo
authors.forename: Oscar
authors.initials: O
authors.lastname: García
authors.forename: Endher
authors.initials: E
authors.lastname: Castillo
authors.forename: Edward
authors.initials: E
authors.lastname: Cardenas
authors.forename: Juan
authors.initials: J
authors.lastname: Marques
authors.forename: Alfredo
authors.initials: A
authors.lastname: Mijares
mesh_terms: D000818:Animals; D014355:Chagas Disease / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D004562:Electrocardiography; D000068800:Etanercept; D007074:Immunoglobulin G / Q000627:therapeutic use*; D007155:Immunologic Factors / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D015203:Reproducibility of Results; D013997:Time Factors; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors; D018754:Ventricular Dysfunction / Q000188:drug therapy; D016276:Ventricular Function / Q000187:drug effects
chemical_list: D007074:Immunoglobulin G; D007155:Immunologic Factors; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D000068800:Etanercept