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Gas exchange during exercise in different evolutional stages of chronic Chagas' heart disease
F P Oliveira1, R C Pedrosa, A Giannella-Neto
1Hospital Universitário Clementino Fraga F masculine, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Insights
Chronic Chagas' heart disease patients show reduced exercise capacity as their condition progresses. Early-stage patients maintain better gas exchange and functional capacity compared to advanced stages.
Area of Science:
- Cardiology
- Exercise Physiology
- Tropical Medicine
Background:
- Chagas' heart disease (CHD) is a progressive condition affecting cardiac function.
- The Los Andes classification system categorizes CHD based on clinical and hemodynamic parameters.
Purpose of the Study:
- To compare gas exchange at rest and during exercise in CHD patients.
- To correlate functional capacity with clinical and hemodynamic status in CHD.
Main Methods:
- Studied 52 CHD patients (Groups IA, IB, II, III) and 15 healthy controls.
- Assessed variables including oxygen consumption (V O2), carbon dioxide production (V CO2), and ventilatory anaerobic threshold (AT).
- Utilized the Los Andes clinical and hemodynamic classification for patient grouping.
Main Results:
- Patients in advanced CHD stages (Groups II and III) exhibited significantly impaired gas exchange and exercise capacity compared to healthy controls.
- Early-stage patients (Group IA) demonstrated better exercise performance than those in advanced stages (Group III).
Conclusions:
- Functional capacity in chronic Chagas' heart disease declines with disease progression.
- Reduced cardiac-hemodynamic performance directly correlates with diminished functional capacity in CHD patients.
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.
Conclusion:
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.