Predicción de riesgo de muerte súbita cardiaca en pacientes chagásicos mediante dinámica simbólica

Abstract

Chagas' disease is a tropical illness characterized by the presence of damage in the myocardium during each stage of the disease, ventricular arrhythmias and sudden death are the main causes of mortality due to disease. In this document we study the characterization of cardiac data from chagasic patients through the application of symbolic dynamics, in order to detect patterns that help us predict the risk of sudden death. The process is made evaluating RR intervals (tachograms) taken from high resolution electrocardiograms (ECGHR) pertaining to 2 kinds of chagasic patients: positives (6 subjects) and negatives (19 subjects) with respect to the cardiopathy test. Data series corresponding to each patient are taken by symbolic dynamics algorithms, which allow represent each value of the tachogram through a symbol. Finally, the symbol chain calculated for each signal is evaluated through entropy analysis, studying the frequency of words of length 3. Also, we look at the original signal searching for reduced amplitude zones (RAZ), and checking if its mean and standard deviation have useful information for this research. The results show the great potential of symbolic dynamics in the characterization of ECGHR signals of chagasics patients, constituting itself as a promising alternative to predict their risk of sudden death. © Springer-Verlag Berlin Heidelberg 2007.