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Chagas' heart disease as an experimental model for studies of cardiac autonomic function in man
Insights
This study reveals that chronic cardiac Chagas' disease impairs autonomic cardiac function due to neuronal degeneration. Chagas' disease serves as a model for studying spontaneous cardiac denervation in humans.
Area of Science:
- Cardiology
- Neurology
- Infectious Diseases
Background:
- Chagas' disease is a parasitic infection that can lead to chronic cardiac complications.
- Cardiac involvement in Chagas' disease can manifest as autonomic dysfunction.
- Previous research has indicated potential autonomic nervous system involvement.
Purpose of the Study:
- To investigate autonomic cardiac function in patients with chronic cardiac Chagas' disease.
- To explore the relationship between neuronal degeneration and cardiac autonomic dysfunction.
- To establish Chagas' disease as a model for studying cardiac denervation.
Main Methods:
- Evaluation of autonomic cardiac function in patients with Chagas' disease and healthy controls.
- Administration of atropine to assess heart rate response.
- Analysis of reflex changes in cardiac rate.
- Inclusion of patients with isolated visceral involvement for comparison.
Main Results:
- Patients with cardiac Chagas' disease exhibited impaired heart rate response to atropine.
- Significantly reduced reflex changes in cardiac rate were observed.
- These findings suggest a functional disorder linked to neuronal degeneration in the sinoatrial region.
- Autonomic dysfunction was a key characteristic in cardiac Chagas' disease patients.
Conclusions:
- Chagas' disease causes spontaneous denervation of the heart.
- The disease provides a valuable model for assessing autonomic control of cardiac function in humans.
- Understanding this dysfunction is crucial for managing cardiac complications.
Abstract:
Patients presented here include apparently healthy persons who had diagnostic evidence of chronic cardiac Chagas' disease in the form of a positive complement-fixation test and an abnormal electrocardiogram. They had never been in heart failure. All were examined for autonomic cardiac function. Normal persons served as controls. Patients with Chagas' disease with sole involvement of hollow viscera were also included. In patients with cardiac Chagas' disease, failure of the heart rate to increase after administration of atropine and greatly reduced reflex changes in cardiac rate are believed to be a functional disorder related to degeneration of the neuronal supply to the sinoatrial region of the heart. It is concluded that Chagas' disease is a model of spontaneous denervation of the heart which may be used for the assessment of autonomic control of cardiac function in man.