Transcutaneous direct current cardioversion in a foal with lone atrial fibrillation.

The research article revolves around a successful medical procedure carried out to rectify a heart condition known as atrial fibrillation in a filly. A less common method, transcutaneous direct current cardioversion, was employed after another standard treatment didn’t work.

Overview of the Research Article

• The study revolves around a rare case of atrial fibrillation (AF) in a 3-month-old Thoroughbred filly, not associated with structural heart disease or within the adaptive period of newborns, making it a unique situation.
• AF is a heart condition that involves an irregular and often rapid heart rate, and this is not commonly reported in foals.

Initial Treatment Attempts

• The researchers first attempted a medical cardioversion—a procedure aimed to bring the heart rate back to normal—using quinidine sulfate, a common treatment for AF in horses.
• However, despite administering three doses, the method was not successful in rectifying the foal’s heart condition.

Alternative Treatment Method

• Given the unsuccessful initial attempts, the researchers turned to an alternative approach, known as timed, transcutaneous, direct current cardioversion.
• This procedure involved using adhesive patches on the midthorax (the middle part of the chest or the thorax) in conjunction with intravenous procainamide, a medication used to treat irregular heartbeats.
• The treatment used a total dose of 20mg/kg of intravenous procainamide.

Successful Outcome of the Alternative Treatment

• The transcutaneous direct current cardioversion successfully brought about a normal sinus rhythm, the natural rhythm of a healthy heart, in the filly.
• The normal sinus rhythm was maintained until the foal’s discharge from the hospital and even at a recheck five months after cardioversion, indicating a successful treatment outcome.

Implications for Future Treatments

• The successful outcome of the case strongly suggests that transcutaneous direct current cardioversion can serve as a potentially effective alternative treatment for similar cases.
• It can especially be beneficial for young or lower body weight horses, where other treatments such as quinidine sulfate or transvenous electrical cardioversion might not yield successful outcomes.