The aim of this study was to evaluate the effect of tranquilization and anesthesia on the indexes of high resolution electrocardiography of dogs with chronic Chagas´ disease.

For such, eight adult female mongrel dogs were submitted to one of the following protocols, accordingly to the group the dog was allocated: (G1) animals with no sedation or anesthesia effect; (G2) tranquilization with acepromazine; (G3) tranquilization with acepromazine and buprenorphine; (G4) inhalatory general anesthesia with isoflurane; (G5) inhalatory general anesthesia with sevoflurane; and (G6) anesthesia with propofol. All dogs were underwent all protocols with a minimum of 15-day intervals between each protocol. High resolution electrocardiography was performed in time domain.

Concerning the electrocardiographic parameters, results showed no significant alterations between groups regarding the duration of QRS complex and LAS40. Similar observations were found for RMS40. By the other hand, the noise level was significantly lower for G4, G5 and G6 when compared to the remaining groups.

It was possible to conclude that anesthesia makes easier the recording of high resolution in dogs and does not cause alterations in the electrocardiographic indexes.