Cardiovascular findings by echocardiography in canine model of Chagas disease immunized with DNA Trypanosoma cruzi genes.

Background: Chagas disease (ChD) is nowadays considered as an emerging disease in the USA and Europe. pBCSP and pBCSSP4 plasmids, containing Trypanosoma cruzi genes encoding a trans -sialidase protein and an amastigote-specific glycoprotein, respectively, were tested as vaccines in canine model. Echocardiography studies for determining the prophylactic effect of these genes in experimentally infected dogs were evaluated to compare with findings obtained by other techniques performed previously. Hemodynamic parameters after DNA-immunization were performed. Results: Low fractional-shortening values of non-vaccinated dogs suggested an impairment in general cardiac function. Low Left-Ventricular-Ejection-Fraction values found in infected dogs suggested myocardial injury regardless of whether they were vaccinated or not. Low Left-Ventricular-Diastolic/Systolic-Diameters in vaccinated dogs suggested that progressive heart damage or heart dilation could be prevented by DNA vaccination. Systolic-Peak-Time was higher in non-vaccinated groups increasing vulnerability to malignant arrhythmias and sudden death. High Left-Ventricular-Volume in infected groups suggested a decrease in wall thickness that might lead to increased size of the heart cavity, except in the pBCSP plasmid-vaccinated dogs. Conclusions: The use of echocardiography allowed a more complete follow-up the pathological process in the living patient than with other techniques like electrocardiography, anatomopathology and histopathology, being the method of choice for characterizing the clinical stages of ChD.