(E09) Transseptal Puncture in the Horse Using Intracardiac Ultrasound Guidance: First Results with Follow-Up

Abstract: Background – Radiofrequency catheter ablation has been successfully applied to treat right atrial tachycardia in horses. Ablation of left-sided arrhythmias is complicated by the perilous retrograde arterial approach needed for left-sided catheterization. In human medicine, the left atrium is accessed femorally through transseptal puncture (TSP) of the fossa ovalis (FO). Recently a TSP technique via the jugular vein was developed for horses.
Hypothesis/Objectives – To determine efficacy, complications and closure process of TSP in horses.
Animals – Three horses without cardiovascular disease, and two horses admitted for ablation of atrial fibrillation (AF).
Methods – Descriptive experimental study. TSP was performed under general anaesthesia by radiofrequency energy application on a guidewire to perforate the FO and allow advancement of a deflectable sheath under transthoracic and intracardiac echocardiographic (TTE and ICE) guidance. In three horses without cardiovascular disease, puncture closure was evaluated during four weeks by TTE and ICE.
Results – All TSPs were successful. Time from sheath positioning in front of the FO until successful transseptal access was 19-97 minutes. In two horses, balloon dilation of the puncture opening was needed for sheath advancement. Minor complications included transient atrial premature depolarisations (n=1), self-terminating atrial tachycardia (n=1) and self-terminating AF (n=1) during radiofrequency energy application for puncture in the horses without pre-existing AF. Follow-up of the closure process (n=3) using ICE showed closure 1-3 weeks after puncture.
Conclusions and clinical importance – TSP could be performed safely in horses using ICE guidance, which opens perspectives for management of left-sided atrial arrhythmias.