LocaLisa - New technique for real-time 3-dimensional localization of regular intracardiac electrodes

Background-Estimation of the 3-dimensional (3D) position of ablation electr odes from fluoroscopic images is inadequate if a systematic lesion pattern is required in the treatment of complex arrhythmogenic substrates. Methods and Results-We developed a new technique for online 3D localization of intracardiac electrodes. Regular catheter electrodes are used as sensor s for a high-frequency transthoratic electrical field, which is applied via standard skin electrodes. We investigated localization accuracy within the right atrium, right ventricle, and left ventricle by comparing measured an d true interelectrode distances of a decapolar catheter, Long-term stabilit y was analyzed by localization of the mast proximal His bundle before and a fter slow pathway ablation. Electrogram recordings were unaffected by the a pplied electrical field. Localization data from 3 catheter positions, widel y distributed within the right atrium, right ventricle, or left ventricle, were analyzed in 10 patients per group. The relationship between measured a nd true electrode positions was highly linear, with an average correlation coefficient of 0.996, 0.997, and 0.999 for the right atrium, right ventricl e, and left ventricle, respectively, Localization accuracy was better than 2 mm, with an additional scaling error of 8% to 14%. After 2 hours, localiz ation of the proximal His bundle was reproducible within 1.4 +/- 1.1 mm. Conclusions-This new technique enables accurate and reproducible real-time localization of electrode positions in cardiac mapping and ablation procedu res. Its application does not distort the quality of electrograms and can b e applied to any electrode catheter.