title: Gas exchange during exercise in different evolutional stages of chronic Chagas' heart disease.
abstract: OBJECTIVE
  To compare gas exchange at rest and during exercise in patients with chronic Chagas' heart disease grouped according to the Los Andes clinical hemodynamic classification.
  
  
  METHODS
  We studied 15 healthy volunteers and 52 patients grouped according to the Los Andes clinical and hemodynamic classification as follows: 17 patients in group IA (normal electrocardiogram and echocardiogram), 9 patients in group IB (normal electrocardiogram and abnormal echocardiogram), 14 patients in group II (abnormal electrocardiogram and echocardiogram, without congestive heart failure), and 12 patients in group III (abnormal electrocardiogram and echocardiogram with congestive heart failure). The following variables were analyzed: oxygen consumption (V O2), carbon dioxide production (V CO2), gas exchange rate (R), inspiratory current volume (V IC), expiratory current volume (V EC), respiratory frequency, minute volume (V E), heart rate (HR), maximum load, O2 pulse, and ventilatory anaerobic threshold (AT).
  
  
  RESULTS
  When compared with the healthy group, patients in groups II and III showed significant changes in the following variables: V O2 peak, V CO2 peak, V IC peak, V EC peak, E, HR, and maximum load. Group IA showed significantly better results for these same variables as compared with group III.
  
  
  CONCLUSIONS
  The functional capacity of patients in the initial phase of chronic Chagas' heart disease is higher than that of patients in an advanced phase and shows a decrease that follows the loss in cardiac-hemodynamic performance.
authors.affiliation: Hospital Universitário Clementino Fraga F masculine, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: F P
authors.initials: FP
authors.lastname: Oliveira
authors.forename: R C
authors.initials: RC
authors.lastname: Pedrosa
authors.forename: A
authors.initials: A
authors.lastname: Giannella-Neto
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D002598:Chagas Cardiomyopathy / Q000503:physiopathology*; D002908:Chronic Disease; D004562:Electrocardiography; D005080:Exercise Test; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D011659:Pulmonary Gas Exchange / Q000502:physiology*