Novel, magnetically guided catheter for endocardial mapping and radiofrequency catheter ablation.

Ablation of complex arrhythmias would be greatly facilitated by more precise control of ablation catheters. A feasibility study was performed in animals to evaluate a novel magnetic guidance system (MGS) that generates a magnetic field to control the movement and position of a magnetic ablation catheter. The MGS is composed of a digital biplanar fluoroscope within an array of superconducting electromagnets that surround the torso of the experimental animal and a computer control system that generates a composite magnetic field for directional catheter deflection. Magnetic catheter navigation was performed in dogs and pigs (20 to 30 kg). A 7F magnetic ablation catheter was used for intracardiac navigation and radiofrequency ablation. The performance of a standard 7F deflectable catheter was not affected by the MGS. The magnetic catheter was navigated successfully to 51 predefined targets throughout the heart in 6 animals. In 5 animals, the magnetic catheter, guided by a 3D computed tomogram, was successfully navigated to all pulmonary veins. Navigation accuracy was estimated as <1 mm displacement from the target. The magnetic catheter was used to ablate the atrioventricular node in 4 animals and to perform linear ablations across the endocardial surface underlying an epicardial multielectrode recording plaque in 4 animals. These results demonstrate that the MGS can navigate and stabilize an ablation catheter at endocardial targets. Linear or focal radiofrequency ablation with the magnetic catheter is not compromised by the magnetic field. This technology provides precise control of endocardial catheters.