# 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.

## Key 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.