Three‐dimensional electro‐anatomical mapping and radiofrequency ablation as a novel treatment for atrioventricular accessory pathway in a horse: A case report

Abstract

We describe the diagnosis and treatment of an atrioventricular accessory pathway (AP) in a horse using 3‐dimensional electro‐anatomical mapping (3D EAM) and radiofrequency catheter ablation (RFCA). During routine evaluation of the horse, intermittent ventricular pre‐excitation was identified on the ECG, characterized by a short PQ interval and abnormal QRS morphology. A right cranial location of the AP was suspected from the 12‐lead ECG and vectorcardiography. After precise localization of the AP using 3D EAM, ablation was performed and AP conduction was eliminated. Immediately after recovery from anesthesia an occasional pre‐excited complex still was observed, but a 24‐hour ECG and an ECG during exercise 1 and 6 weeks after the procedure showed complete disappearance of pre‐excitation. This case shows the feasibility of 3D EAM and RFCA to identify and treat an AP in horses.

Early recognition with capnography, and successful resuscitation, of severe cardiac dysfunction in a horse receiving amiodarone during transvenous electric cardioversion (TVEC)

“…In human medicine, radiofrequency ablation would have been used to treat the underlying cause of the AF. Although this technology has not yet been fully developed in horses, the treatment of other arrhythmias, such as sustained atrial tachycardia and an accessory pathway, has been reported (Buschmann et al, 2023; Phillips et al, 2022; Van Steenkiste et al, 2022).…”

Anti‐arrhythmic drugs before, during and after transvenous electrical cardioversion of atrial fibrillation in horses: Weighing the benefits and risks

“…Finally, 3D electroanatomical mapping followed by radiofrequency ablation is a promising tool for arrhythmia treatment as this therapy also deals with the underlying causal mechanism and thus reduces the risk for recurrence (van Loon et al., 2020). Successful ablation has been described for focal and macro‐re‐entrant AT (Van Steenkiste et al., 2022) and for an atrioventricular accessory pathway (Buschmann et al., 2023). For horses with AF, electroanatomical mapping and ablation therapy could potentially be useful to reduce the arrhythmogenic substrate, especially in those horses which present focal or macro‐re‐entrant AT as the underlying mechanism.…”

Morphological and histological investigation of the conduction system in the equine atrial muscle sleeve of pulmonary veins

“…[5][6][7][8] Mapping of the whole heart was performed in 2020, 9 and mapping and radiofrequency ablation of atrial tachycardia and an accessory pathway was also described earlier. 10,11 However, the available information on anatomical, histological and immunohistochemical assessment of the pulmonary vein ostia and the conduction system of the myocardial sleeve is still obscure in this species. [12][13][14] After the common pulmonary vein is canalised during human heart development, it attaches to the left atrium initially with one single orifice.…”