Peer-reviewed veterinary case report
Idiopathic atrial fibrillation in a champion Standardbred racehorse.
- Journal:
- Australian veterinary journal
- Year:
- 1990
- Authors:
- Stewart, G A et al.
- Affiliation:
- School of Veterinary Science · Australia
- Species:
- horse
Plain-English summary
A champion Standardbred racehorse, who had previously been named Australian Harness Horse of the Year at just 3 years old, developed a heart condition called atrial fibrillation, which is an irregular heartbeat. This condition lasted for at least six weeks, during which the horse did not race. The horse was treated successfully with a medication called quinidine, given through a tube, after being stabilized with another medication called digoxin over four days. Remarkably, just four hours after starting the treatment, the horse's heart rhythm improved, and ten minutes later, it returned to normal. After recovering, the horse performed just as well as before and even set a new track record at a major racetrack in Melbourne, showing that the treatment was effective and that there were no lasting heart issues.
Abstract
Atrial fibrillation is described in a champion pacer which earlier had been named Australian Harness Horse of the Year as a 3-year-old in 1986-87. Prior to conversion atrial fibrillation had been present for at least 6 weeks, during which the horse had not raced. Successful treatment was achieved with two 10g doses of quinidine sulphate per oesophageal tube, after slow digitalisation with intravenous digoxin over 4d. Four hours after commencement of quinidine therapy the arrhythmia had regressed to atrial flutter and converted to sinus rhythm 10 min later. Considering his age, standard of racing and high reputation the horse's overall performance as a 5-year-old after conversion from atrial fibrillation appeared comparable to his previous performance as a 4-year-old before the disorder occurred. In one of the wins since his return to sinus rhythm, the horse recorded his fastest winning speed and created a new track record at the major Melbourne racetrack. The absence of abnormalities of atrial and atrio-ventricular conduction after the cessation of the arrhythmia, together with the horse's return to successful racing, indicate that this was case of atrial fibrillation occurring as a functional disorder without persistent atrial pathology.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/2378602/