Treatment of ventricular arrhythmias with oral sotalol in four horses

Sustained ventricular arrhythmias (VAs) in horses can require medical intervention. Prompt pharmacological treatment is indicated when the arrhythmia leads to hemodynamic or electrical instability. Established antiarrhythmic treatment of VA in horses includes lidocaine and magnesium, administered parenterally. Other antiarrhythmic agents are used; however, concerns regarding adverse effects, financial restrictions, logistics of administration, and lack of access often limit their use. While anecdotal reports of oral administration of sotalol for treatment of VA in horses exist, sotalol has primarily been described for prevention of recurrent atrial fibrillation or suppression of supraventricular and ventricular ectopy. This case series describes 4 horses with sustained VA treated orally with sotalol. Successful conversion to a predominantly normal sinus rhythm or pre-existing atrial fibrillation was achieved without any adverse effects. Sotalol could be considered as a treatment option in selected, hemodynamically stable cases of VA, especially where other established treatment options are unavailable, ineffective, or unaffordable.