Chagas' cardioneuropathy: Cardiovascular autonomic dysfunction as the first manifestation of the disease

Chagas' disease is a leading cause of cardiac arrhythmias, congestive heart failure, autonomic nervous system dysfunction, and sudden death in endemic areas of the American continent. It is also a major cause of chronic myocarditis, and the apical aneurysm is a distinctive pathological marker of the disease. Wall motion abnormalities, either segmental or diffuse, are another important clinical feature of the disease. Information regarding geographical distribution, frequency, and appearance of the autonomic dysfunction at the different stages of the disease is still lacking. A group of 181 patients with Chagas' disease were studied in Venezuela. Clinical and physiological tests showed abnormalities in cardiovascular reflexes, making it possible to confirm the presence of autonomic nervous system dysfunction in Venezuela, as well as in other patients with Chagas' disease previously described in other countries. Chagas' disease patients showed a high incidence of autonomic nervous system dysfunction (54%) which occurred in the three stages of the evolution of this disease, being frequently found during the initial stage in young, asymptomatic, cardiovascular patients. Autonomic dysfunction may be the first and only sign of the disease in this subgroup, and it cannot be related to age or heart failure.