Treatment of atrial fibrillation in the horse with intravenous dihydroquinidine gluconate.

The study investigates the use of intravenous dihydroquinidine gluconate as a potential alternative in the treatment of atrial fibrillation in horses, suggesting the method may help overcome various challenges associated with the commonly used method of oral quinidine sulphate administration.

Background

• The research is centered on the treatment of atrial fibrillation in horses – a health condition in which the upper chambers of the heart, the atria, beat irregularly, leading to a chaotic and inefficient flow of blood.
• Traditionally, oral administration of quinidine sulphate has been considered the preferred treatment method for this condition. However, this method has various known difficulties, such as the risk of toxicity due to high dosage levels, the danger of acute laminitis (a painful inflammation in the foot of the horse), causing distress to the horses by repeated balling or passing of the stomach tube, and the safety risk posed by unruly horses to the individuals administering the drug.

Purpose of the Study

• Given these issues, the research sets out to examine an alternative treatment method for atrial fibrillation in horses. The researchers consider dihydroquinidine gluconate, admininstered intravenously, as a potential solution to overcome the issues associated with oral administration of quinidine sulphate.

Description of Cases

• The researchers intend to discuss two case studies. One horse was treated with traditional oral doses of quinidine sulphate (at unusually high dosage levels), while the other was the first horse at their clinic to be treated with intravenous dihydroquinidine gluconate.
• Both horses used in the study were 8-year-old geldings (castrated male horses) and international show jumpers. They were known to end their rounds in an exhausted state, and according to referring veterinarians, both had suffered from atrial fibrillation for at least a year before they were admitted to the clinic.

Methodology

• After admission, each horse was examined daily with electrocardiograms recorded before treatment and afterwards when necessary. Additional electrocardiograms were taken whenever the horses were ridden, both before and after the exercise.
• Haematological examinations were carried out at least once or twice each week and included packed cell volume, haemoglobin estimations, and red and white cell counts. In one case, more in-depth observations consisted of weekly tests of enzyme activities, and estimations of bilirubin, cholesterol, urea, iron, and copper concentrations.