The Relationship Between Nonlinear Heart Rate Variability and Echocardiographic Indices in Chagas Disease

Chagas disease (CD) is caused by the protozoan Trypanosoma cruzi and chronic cardiomyopathy (CC) is its most frequent and ominous consequence. The risk of death of patients with CD has been related to demographic, electrocardiographic-radiological-ultrasonographic and Holter parameters. Cardiac dysautonomia has also been demonstrated and may contribute to the pathogenesis of CC. We hypothesize that heart rate variability (HRV) indices are related to cardiac dysfunction as evaluated with echocardiography, and may configure a noninvasive prognostic marker in patients with CD. Short-term (15 min) cardiac interval series of 23 patients with CD were analyzed using 15 HRV indices and correlated to 7 morpho-functional echocardiographic parameters. Results showed that echocardiographic parameters are correlated with HRV indices, and that distribution entropy seems to be an important index for noninvasive prognostication of CD.