Eric J. Voth

Validation of Computed Tomography Image Integration into the EnSite NavX Mapping System to Perform Catheter Ablation of Atrial Fibrillation

Introduction: The complex anatomy of the left atrium (LA) makes location of ablation catheters difficult using fluoroscopy alone, and therefore 3D mapping systems are now routinely used. We describe the integration of a CT image into the EnSite NavX System with Fusion and its validation in patients undergoing atrial fibrillation (AF) or left atrial tachycardia (AT) catheter ablation.

Estimates of Endocardial Potentials from Non-contact Intracavitary Probes

The EnSitetrade intracavitary probe system developed by Endocardial Solutions, Inc (St. Jude Medical, St. Paul, MN) was used to simultaneously record geometric information, probe potentials, and selected endocardial potentials within the right atria for four patients. Tikhonov regularization was then used to estimate endocardial potentials from probe measurements for each patient at each endocardial site. The correlation coefficients and relative errors between the estimated potentials and the measured endocardial potentials were then calculated. This inverse problem was quite ill-conditioned, and first-order Tikhonov regularization performed better than zero-order or second-order Tikhonov regularization in producing stable and accurate results. In choosing the regularization parameter mu, a constant value of mu=0.3 performed as well as CRESO and maximum curvature, which pick a different mu for each time instant