Abstract P2136: TpTe Interval Behavior And Mortality In Wistar Rats Submitted To Cardiac Ischemia And Reperfusion Treated With The Heparin Fragment Trisulfated Disaccharide

Abstract

Introduction: The Tp-Te ekg interval reflects ventricular transmural dispersion, being used for prediction of ventricular arrhythmia and sudden death. The heparin fragment called Trisulfated Disaccharide (TD), which has no effect on blood coagulation and acts on the sodium-calcium exchanger accelerating the output of calcium from the cell, decreases cytoplasmic calcium concentrations in situations of calcium overload due to ischemia and reperfusion (I-R). Objective: To evaluate the behavior of the Tp-Te interval and mortality due to cardiac arest in Wistar rats submitted to surgicaly induced I-R under treatment with TD at reperfusion. Materials and Method: Wistar rats (n=8) with average weight of 300g were anesthetized and under assisted breathing were electrocardiographically monitored and submitted to surgical cardiac ischemia by ligation of the anterior descending artery for 10 min, with reperfusion thereafter. The Tp-Te interval was analyzed before ischemia, at 10 min after ischemia induction and at 10 min after reperfusion, The incidence of arrhythmias was determined throughout the recording period. In the study group intravenous (0.2 mg/kg) TD was injected concomitantly with the reperfusion. In the control group (n=8), the same procedure was performed, without the TD infusion. Results: During ischemia there was a similar alteration of the Tp-Te interval in both groups when compared to the pre-ischemic phase, with an increase of about 90% in magnitude, as well as the presence of ventricular arrhythmias, without animal mortality. During reperfusion Tp-Te interval returned to normal in the treated group and there was no mortality. In the control group, the magnitude of the Tp-Te increase was maintained. The presence of ventricular arrhythmias was similar, but total atrioventricular block and/or sustained arrhythmia occurred in 50% of the animals, followed by animals death. Conclusion: Treatment with TD at the time of reperfusion normalized the Tp-Te interval 10 min after TD infusion as well as reduced mortality in wistar rats submitted to I-R, and may be useful in the protection of organs submitted to the same I-R conditions (transplants, surgical and hemodynamic procedures), where calcium overload is determinant in morbidity and mortality.