Nonfluoroscopic localization of intracardiac electrode-catheters combined with noncontact electrical-anatomical imaging

We recently combined noncontact mapping and intracardiac echocardiography (ICE) in a single catheter-system that permitted 3D electrical-anatomical imaging of the heart. The objective of the present study was to develop a nonfluoroscopic method to localize standard, navigational electrode-catheters, which also operated in conjunction with noncontact electrical-anatomical imaging. Accordingly, electrode-catheters were fixed at the endocardium in the LV of three dogs and in the RA of two other dogs. A catheter-system was placed inside the heart cavity, and consisted of a 9-F sheath carrying a coaxial noncontact 64-electrode lumen-probe on the outside (diameter = 7 mm), and a central ICE catheter on the inside (9 MHz). To reconstruct the endocardial anatomy, the ICE catheter was pulled back inside the sheath and multiple 2D tomographic images were acquired. The noncontact probe was then advanced over the sheath and into the heart cavity. Current pulses were injected into the endocardial contact electrodes and all probe electrodes sensed corresponding potentials. Measured probe potentials localized the endocardial electrodes based on the least squares numeric method, and was verified by ICE. We found that the 3D endocardial geometry reconstructed by ICE depicted important anatomical details. All endocardial electrodes were identified by ICE and were correctly matched with corresponding endocardial anatomy. The difference in computed electrode locations compared to ICE was 5.4 +/- 2.4 mm (n = 10). In conclusion, nonfluoroscopic localization of standard navigational electrode-catheters within true and detailed 3D images of cardiac anatomy is feasible. Integrating this approach with noncontact electrical-anatomical imaging could facilitate diagnosing arrhythmias and advancing their therapy.