Postsurgical ventricular tachycardia in a horse.

A 2-year-old Thoroughbred racehorse developed ventricular tachycardia after elective laryngoplasty and ventriculectomy were performed while anesthesia was maintained with halothane. During surgery, the horse became febrile and developed transient mild hypercarbia. The horse was treated with an IV infusion of quinidine gluconate. Continuous electrocardiographic monitoring was used to evaluate cardiac rhythm during treatment, and conversion was achieved after 12 hours of IV infusion. The inciting cause for the arrhythmia was not determined.