مطالعه اثر تجويز خوراكي والپروات سديم بر تغييرات الكتروكارديوگرام در گربه

Effect of orally administrated sodium valproate on alternations in the electrocardiogram of the cat

Valproic acid is a fatty acid with antiseizure. Currently the salts of valproic acid are used to treat seizure, bipolar disorders and to prevent migraine in human and animals. Valproate sodium inhibits repetitive bursting action potentials of cells. Furthermore it has been shown that high concentrations of valproate can increase potassium transmission across cellular membranes while in low concentrations it can lead to cellular hyperpolarisation. Considering that there are Na+ and K4 channels on the surface of cardiomyocytes, it is probable that sodium valproate can affect these channels as well. Therefore in the present study it was attempted to investigate the effect of orally administered sodium valproate on alterations in the electrocardiogram of the cat. In this experimental study, 8 domestic short hair male cats that were selected randomly were used, valproate sodium was administered orally to all animals at the dose of 50 mg/kg daily for 3 weeks and the electrocardiogram was recorded at days 0 ( prior to drug administration) , 7, 14 and 21 during drug administration in lead II. Heart rate (HR), P wave duration (PD), P wave amplitude ( PA), PR interval (PR- interval), QRS duration( QRS D), R amplitude (RA), ST segment ( ST seg.) and QT interval( QT int.) were evaluated from the electrocardiogram. The results indicate that heart rate and R amplitude(RA) at days 7, 14 and 21 had significantly increased and decreased respectively compared with day 0 (P<0.05) . These results revealed that valproic acid induces sinus tachycardia in the cat. It is evident from this finding together with the decrease in R wave amplitude that this drug has positive inotropic and negative chronotropic effects and it seems that through these effects it may bring about proarrythmic effect in the cat.