[Chagas cardiomyopathy and the autonomic nervous system. Clinical studies]

The autonomic nervous system is abnormal in patients with advanced Chagas'heart disease. Most researchers consider these autonomic abnormalities as primary, specific and irreversible. However, when and why do these abnormalities appear in the natural history of Chagas'disease, is still the subject of intense controversy. Recent morphological and functional studies strongly suggest that, the sympathetic and the parasympathetic abnormalities, are preceded by myocardial damage and left ventricular dysfunction. Consequently, the cardiac parasympathetic abnormalities and the activation of the sympathetic and of the renin-angiotensin-aldosterone systems of chagasic patients are very likely secondary and partially reversible. Therefore, neurohormonal activation, as postulated by the neurogenic theory could contribute to the progression of myocardial damage and left ventricular dysfunction. Additional clinical investigations are necessary to clarify this important issue.