Dexmedetomidine in Healthy Dogs: Impact on Electrocardiographic Parameters

TL;DR

This study shows that giving dexmedetomidine to healthy dogs causes slower heart rates and changes in heart electrical activity, but not in blood pressure.

Contribution

The study provides new empirical evidence on the electrocardiographic effects of intravenous dexmedetomidine in healthy dogs.

Findings

Dexmedetomidine caused significant bradycardia in healthy dogs.

ECG parameters like P wave, QRS complex, PR interval, and QT interval increased significantly.

QTc interval decreased significantly, while blood pressure remained unchanged.

Abstract

Objective: To evaluate whether intravenous administration of dexmedetomidine alters the electrocardiographic parameters of healthy dogs.

Animals: 22 healthy dogs.

Study Design: prospective blind clinical trial.

Materials and Methods: The dogs underwent electrocardiographic monitoring at two moments: baseline moment (MB), subjected to tranquilization with butorphanol (0.25 mg/kg/IM), and dexmedetomidine moment (MDEX), after 10 min of intravenous administration of dexmedetomidine (bolus of 2 μg/kg, in 2 minutes, followed by continuous infusion at a rate of 2 μg/kg/hour).

Results: After intravenous administration of dexmedetomidine, sinus bradycardia predominated. Regarding electrocardiographic parameters, there was a significant increase in the duration of the P wave (44; 51 ms), QRS complex (62; 67 ms), PR interval (95; 126 ms), and QT interval (207; 252 ms) and reduction in the QTc interval (249; 226 ms), without significant change in systolic, mean, and diastolic blood pressure.

Conclusion: Intravenous administration of dexmedetomidine in healthy dogs results in increased parasympathetic tone with significant reduction in heart rate and increased conduction time of electrical impulses in the myocardium.

Figures