Dataset: Successful caudal vena cava and pulmonary vein isolation in healthy horses using 3D electro-anatomical mapping and a contact force-guided abaltion system

Background: Recently, treatment of equine atrial tachycardia by three-dimensional electro-anatomical mapping (3D EAM) and radiofrequency catheter ablation (RFCA) has been described. Myocardial sleeves in the caudal vena cava and pulmonary veins are a potential trigger for initiation and perpetuation of atrial tachycardia and atrial fibrillation in the horse. Isolation of these myocardial sleeves by RFCA may be an effective treatment for these arrhythmias.Objectives: To describe the feasibility of 3D EAM and RFCA to isolate caudal vena cava and pulmonary veins in adult horses using 3D mapping and a contact force (CF)-guided ablation system.Study Design: In vivo experiment.Methods: 3D EAM and RFCA was performed in five horses without cardiovascular disease under general anaesthesia, using the CF-guided system CARTO®3. Point-by-point RFCA aimed for isolation of caudal vena cava and pulmonary veins. Radiofrequency energy was delivered in power-controlled mode with a target power of 45 W, CF between 10-15 g and 30 ml/min irrigation rate, until an ablation-index of 450-500 was reached.Results: In the right atrium, myocardial sleeves of the caudal vena cava were isolated (n=5). In the left atrium, isolation of ostium II (n=3), ostium III (n=1) and ostium I, II and III <i>en bloc </i>(n=1) was performed. Successful isolation was confirmed by entrance and exit block.Main limitations: Horses were euthanized at the end of the procedure, so long term effects such as potential reconnection of isolated veins could not be studied.Conclusions: This is the first description of 3D EAM and RFCA with CARTO® 3 in horses, thereby showing the technical feasibility and successful caudal vena cava and pulmonary vein isolation. CF measurement allowed monitoring of catheter-tissue contact, resulting in efficient acute lesion creation as confirmed by entrance and exit block. This is a promising treatment for cardiac arrhythmias in horses.