Radiofrequency catheter ablation of a concealed accessory pathway of the heart in a Labrador Retriever

Abstract

The presence of an accessory atrioventricular conduction pathway may provide the anatomical basis for some tachyarrhythmias. Persistent tachyarrythmias may result in the development of systolic dysfunction or tachycardiomyopathy and eventual progression to heart failure. In this paper we report the successful ablation of an accessory pathway involved in the pathogenesis of persistent orthodromic atrioventricular reciprocating tachycardia (AVRT) and heart failure in a 3-year-old male Labrador Retriever. Electrophysiological study and radiofrequency (RF) catheter ablation were performed under general anesthesia. Electrophysiological study revealed AVRT resulting from a retrograde conduction via a right posteroseptal accessory pathway. The successful RF ablation of the accessory pathway resulted in the resolution of the tachycardia and return of normal sinus rhythm. Medical management of heart failure was withdrawn and no episodes of recurrent tachyarrhythmia were documented during a 3-month follow-up.