Abstract

The effect of Trypanosoma brucei infection on changes in concentration of some serum electrolytes and the consequence of these changes on electrocardiographic (ECG) indices were investigated in dogs. The nature of association between each of the electrolytes and the various ECG indices were studied at different days during the infection.  The serum concentration of sodium, potassium and calcium were assayed before and at 8th, 16th, and 24th days after infection in dogs. The ECG was also recorded concurrently with serum electrolyte assay in each dog. The infection, although it caused a significant change in serum sodium (P≤0.001) and potassium ion concentration (P≤0.01) of the dogs, it did not significantly affect their serum calcium ion concentration. (P≥0.05). There was no difference between the serum sodium and potassium levels of arrhythmic and non-arrhythmic dogs but serum calcium concentration of arrhythmic dogs was higher than that of non-arrhythmic ones. The QT, RR Variability, QT and QT_C width correlated strongly and significantly with serum sodium, potassium and calcium at different times during the period of infection. There was a significant correlation between calcium and heart rate on the 16th and 24th day of infection.  Potassium correlated with T/R and the R wave voltage at various times during the infection In conclusion, T. brucei infection affected the serum electrolytes concentration and may have caused ECG changes through mechanism that involves the modulatory responses of the autonomic nervous system and the ion channels.

Keywords: Calcium, Electrocardiogram, Potassium, Sodium, Trypanosoma brucei