title: Left atrial dysfunction in chagas cardiomyopathy is more severe than in idiopathic dilated cardiomyopathy: a study with real-time three-dimensional echocardiography.
abstract: BACKGROUND
  Although there is anatomopathologic evidence of atrial involvement in Chagas cardiomyopathy (CCM), the impact in left atrial (LA) function is unknown. The aim of this study was to evaluate LA function in patients with CCM with real-time three-dimensional echocardiography (RT3DE) and to compare it with patients with idiopathic dilated cardiomyopathy (DCM).
  
  
  METHODS
  A total of 30 patients with CCM, 30 patients with DCM, and 20 normal subjects used as the control group were studied. With the use of RT3DE, we measured LA maximum (maxLAV), minimum, and pre-atrial contraction volumes and calculated total and active LA emptying fractions.
  
  
  RESULTS
  Left ventricular ejection fraction and mitral regurgitation were similar in both groups. MaxLAV/m(2) was larger in the CCM group than in the DCM group (76.9 ± 21.9 mL vs. 59.1 ± 26.0 mL; P < .01), and both were significantly larger than in the control group (P < .01). Total LA emptying fraction was lower in the CCM group than in the DCM group (0.30 ± 0.10 vs. 0.40 ± 0.12; P < .01), and both were lower than in the control group (P = .01). Active LA emptying fraction was also lower in the CCM group than in the DCM group (0.22 ± 0.09 vs. 0.28 ± 0.11; P < .01), and both were lower than in the control group (P = .01). The E/e' ratio was higher in the CCM group than in the DCM group (21 ± 10 vs. 15 ± 6; P < .01), and both were greater than in the control group (P < .01). In a multiple regression model, the E/e' ratio was the only independent predictor of a worsening active LA emptying fraction.
  
  
  CONCLUSIONS
  LA function is more compromised in patients with CCM than in patients with DCM. This finding indicates a more diffuse and severe myocardial impairment in Chagas disease that is probably related to increased left ventricular filling pressures and atrial myopathy.
authors.affiliation: Discipline of Cardiology, Department of Internal Medicine, Federal University of São Paulo, Sao Paulo, Brazil.
authors.forename: Frederico J N
authors.initials: FJ
authors.lastname: Mancuso
authors.forename: Dirceu R
authors.initials: DR
authors.lastname: Almeida
authors.forename: Valdir A
authors.initials: VA
authors.lastname: Moisés
authors.forename: Wercules A
authors.initials: WA
authors.lastname: Oliveira
authors.forename: Eduardo S
authors.initials: ES
authors.lastname: Mello
authors.forename: Dalva
authors.initials: D
authors.lastname: Poyares
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
authors.forename: Antonio C C
authors.initials: AC
authors.lastname: Carvalho
authors.forename: Orlando
authors.initials: O
authors.lastname: Campos
mesh_terms: D016279:Atrial Function, Left; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000473:pathology; D016022:Case-Control Studies; D002598:Chagas Cardiomyopathy / Q000000981:diagnostic imaging* / Q000473:pathology; D003199:Computer Systems; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000473:pathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000473:pathology; D015999:Multivariate Analysis; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods; D012720:Severity of Illness Index; D013318:Stroke Volume; D013997:Time Factors; D014463:Ultrasonography; D016277:Ventricular Function, Left