Non-Fluoroscopic Transseptal Catheterization During Electrophysiology Procedures using a Remote Magnetic Navigation System

Abstract

Transseptal punctures are commonly performed, and left atrial (LA) access is frequently lost during lengthy, complex electrophysiology (EP) procedures. We describe a new technique for non-fluoroscopic re-crossing the fossa ovalis using a new multielectrode transseptal sheath (TS) and a new remote magnetic catheter navigation system (RMNS) (CGCI System, Magnetecs) that uses 8 rapid external electromagnets for real-time navigation of a magnet-tipped electrode catheter across the initial transseptal puncture site in 5 patients undergoing left-sided ablation procedures. The three-dimensional (3D) position of a 8.5 Fr steerable TS with 5-ring 5-15-15-5-mm spaced distal electrodes (Agilis ES©, St Jude Medical), and site of fossal ovalis crossing were "shadowed landmarks" on a 3D electroanatomic mapping (EAM) system (EnSite/NavXTM, St Jude Medical). The TS-magnetic ablation catheter assembly was pulled-back to the inferior vena cava. EAM landmarks were used with RMNS-guided "manual" and "automated" catheter navigation modalities, until septal crossing was obtained. Transseptal re-crossing was successfully performed in all patients in 6.2±8.1 sec using the "automated" RMNS-guided technique and in 30.4±28.4 sec using the "manual" RMNS-guided technique (p=0.01) without complications. This new RMNS was safely and effectively used to perform non-fluoroscopic transseptal catheterization.

Keywords: Catheter Ablation; Fluoroscopy; Left Atrium Access; Remote Navigation; Transseptal Catheterization.

Figure 1.. : EnSite images of RMNS-guided catheter septal crossings. Panels A through D show the transseptal progression of the magnetic-tipped catheter from the inferior vena cava to the LA. LAO and RAO projections of the EAM are seen in each panel. The magnetic tipped ablation catheter is pointed towards a transseptal pathway “shadow” using a “manual” joystick-driven RMNS. The “shadow” is best seen in the LAO projections. The red arrow in panels B and C identifies the magnetic tipped catheter at the transseptal “shadow.” A coronary sinus (CS) catheter is also seen in each image. The yellow arrow depicts the direction in which the RMNS is pointing the ablation catheter magnetic tip.

Figure 2.. RMNS-guided catheter septal crossing. After withdrawal of the transseptal sheath and the magnetic-tipped catheter into the RA, automated remote navigation via the CGCI system was used for guiding the catheter across the septum. The operator first tagged a spot on the left atrial side of the septum (seen on LAO view as a light blue dot labeled “1”); upon automated crossing of the septum, the operator assumed control of magnetic navigation of the catheter via the joystick and navigated the catheter to the left and right superior veins, respectively.