Catheter Ablation of Complex Tachyarrhythmias Using Remote Magnetic Catheter Navigation System

Abstract

Over the past 30 years, a number of different techniques and energy sources have been developed for catheter ablation of complex tachyarrhythmias, including atrial fibrillation (AF) and ventricular tachycardia (VT).1-3 Radiofrequency (RF) current is the most commonly utilized energy source for ablation. Saline irrigation of an RF ablation electrode provides greater electrode–tissue interface cooling, allowing more sustained power delivery with greater lesion formation and lower risk of thrombus formation.4 Although RF ablation has been proven to be effective, there continue to be several limitations, including relatively long procedure times (causing significant operator fatigue) and radiation exposure for both operators and patients. The heavy lead aprons may cause operators spinal injury. Catheter manipulation is often challenging and requires significant operator skill and experience, especially in dilated atria or ventricles. Access to the required cardiac chamber is sometimes limited, such as in patients with complex anatomy and/or congenital heart disease. These difficulties often lead to incomplete mapping and/or poor lesion formation due to inadequate catheter contact.5 The remote magnetic catheter navigation (RMN) system (Niobe/Epoch, Stereotaxis, Inc., St. Louis, MO, USA) has been developed for robotic catheter control to address these limitations. The system has two large computer-controlled magnets, located on each side of the patient, that generate a magnetic field vector (0.08 or 0.10 Tesla) in any direction at the center of the patient's chest to control catheter movement.6-8 The RMN system utilizes a soft, flexible mapping/ablation catheter with three magnets to respond to the external magnetic field, and then can be advanced or retracted remotely using a catheter-advancer system (Cardiodrive, Stereotaxis, Inc). A 3-D electroanatomical mapping system (CARTO-RMT, Biosense Webster, Inc., Diamond Bar, CA, USA) has been integrated for use with the RMN system. The mapping/ablation catheter has a saline irrigated tip electrode and a location sensor for the electroanatomical mapping system (ThermoCool RMT, Biosense Webster, Inc.). This supplement describes the impressive recent progress using the RMT system for catheter ablation in patients with complex tachyarrhythmias, including AF, atrial tachycardia, and VT. I thank Drs. Nakagawa and Natale for their expertise and hard work as Guest Editors of this supplement. Because of a personal conflict of interest with Stereotaxis, I have not been involved in the selection of articles or in the review process–Eric N. Prystowsky, MD.