Eletrocardiograma de equinos sedados com xilazina ou detomidina no acuponto VG1

Abstract

Alpha-2 adrenergic agonists, such as xylazine and detomidine, are drugs widely used in equine clinical and surgical practice for sedative, muscle relaxant, and analgesic purposes. The use of these drugs is commonly associated with cardiovascular side effects, making electrocardiographic monitoring important, especially for the detection of arrhythmias and conduction disturbances. Pharmacopuncture has been shown to be an alternative for reducing doses and minimizing adverse effects, with GV1 being an acupoint used to potentiate sedative drugs. This study aimed to evaluate the electrocardiographic data of subdose administration of xylazine (0.33 mg/kg) and detomidine (0.013 mg/kg) in horses, comparing the intravenous route with pharmacopuncture at the GV1 acupoint. Twenty-four clinically healthy horses were randomly assigned to four groups: intravenous xylazine (XIL IV), xylazine at the GV1 acupoint (XIL GV1), intravenous detomidine (DET IV), and detomidine at the GV1 acupoint (DET GV1), all receiving 1/3 of the conventional dose. Electrocardiographic parameters were recorded before and every 15 minutes after administration, over a two-hour period. A trend of heart rate reduction was observed in all groups, more pronounced in the first 30 minutes, especially in DET IV, without significant statistical differences. PR and QT intervals showed a slight increase correlated with heart rate reduction, but remained within physiological values for the species. No significant changes were observed in the amplitude or duration of P waves, QRS complexes, T waves, or %T/R ratio. It is concluded that pharmacopuncture at the GV1 acupoint, with subdoses of xylazine or detomidine, did not cause significant adverse electrocardiographic effects, showing responses similar to intravenous administration, and appears to be safe for equine sedation under the studied conditions.