A NOVEL METHOD FOR NONFLUOROSCOPIC CATHETER-BASED ELECTROANATOMICAL MAPPING OF THE HEART - IN-VITRO AND IN-VIVO ACCURACY RESULTS

Background Cardiac mapping is essential for understanding the mechanis ms of arrhythmias and for directing curative procedures. A major limit ation of the current methods is the inability to accurately relate loc al electrograms to their spatial orientation. The objective of this st udy was to present and test the accuracy of a new method for nonfluoro scopic, catheter-based, endocardial mapping. Methods and Results The m ethod is based on using a new locatable catheter connected to an endoc ardial mapping and navigating system The system uses magnetic technolo gy to accurately determine the location and orientation of the cathete r and simultaneously records the local electrogram from its tip. By sa mpling a plurality of endocardial sites, the system reconstructs the t hree-dimensional geometry of the chamber, with the electrophysiologica l information color-coded and superimposed on the anatomy. The accurac y of the system was tested in both in vitro and in vivo studies and wa s found to be highly reproducible (SD, 0.16 +/- 0.02 [mean +/- SEM] an d 0.74 +/- 0.13 mm) and accurate (mean errors, 0.42 +/- 0.05 and 0.73 +/- 0.03 mm). In further studies, electroanatomical mapping of the car diac chambers was performed in 34 pigs. Both the geometry and activati on sequence were repeatable in all pigs. Conclusions The new mapping m ethod is highly accurate and reproducible. The ability to combine elec trophysiological and spatial information provides a unique tool for bo th research and clinical electrophysiology. Consequently, the main sho rtcomings of conventional mapping-namely, prolonged x-ray exposure, lo w spatial resolution, and the inability to accurately navigate to a pr edefined site-can all be overcome with this new method.