Effects of sedation with acepromazine on echocardiographic measurements in eight healthy thoroughbred horses.

This research studied the effects of a sedative, acepromazine, on the measurements observed in echocardiography (a test to visualize the heart) in eight healthy thoroughbred horses. It was noted that after sedation, there were significant changes in some heart dimensions, while others and the heart function remained unaffected.

Methodology

• The researchers performed echocardiography on eight healthy thoroughbred horses under two conditions: while completely alert, and then after sedation using the drug acepromazine.
• The dose of acepromazine administered was 0.03 mg/kg, given intravenously to each horse.
• After a period of 10 minutes had elapsed post-administration of the sedative, subsequent echocardiographic measurements were taken.

Findings

• The study recorded significant increases in certain heart dimensions as a result of the sedation. These included the diameters of the pulmonary artery and the aorta (measured at the end of the heart’s contraction phase), and the thickness of the interventricular septum (measured at both end of contraction and relaxation phases).
• A significant decrease was observed in the diameter of the left atrium of the heart, measured at the end of the relaxation phase.
• However, other cardiac dimensions were found to be unaffected by the sedation. The indices of cardiac function (which are indicators of the working and efficiency of the heart) also showed no changes after the administration of the sedative.
• Moreover, the study did not find any effect on the occurrence and severity of the condition termed as ‘valvular regurgitation’ (a condition where the heart’s valve doesn’t close tightly, which can lead to blood backwards flow).

Conclusion

• The research concluded that sedation with acepromazine in horses affects certain echocardiographic measurements, eliciting changes in certain heart dimensions. However, it doesn’t impact other dimensions, overall cardiac function, or the occurrence and severity of valvular regurgitation.
• These findings provide important information for veterinarians and researchers when considering the use of sedation for echocardiographic analysis in horses.