Special treatments for valve/hole regions in endocardial potential estimates from non-contact intracavitary probes.

The EnSite intracavitary probe system developed by Endocardial Solutions, Inc (St. Jude Medical, St. Paul, MN) was used to simultaneously record geometric information, probe potentials, and endocardial potentials within the right atria for four patients. First-order Tikhonov regularization was then used to estimate endocardial potentials from the probe potentials for each patient at each endocardial site, and relative errors and correlation coefficients between the estimates and measured data were computed. Next, three treatments for valve/hole regions of the heart were examined to determine whether they were able to improve the endocardial potential estimates outside the valve/hole regions: thetaphi/theta(n) = 0, c thetaphi/theta(n) = phi, and infinite elements. The correlation coefficients and relative errors for the estimates with the special treatments were extremely close to (and sometimes slightly worse than) the estimates without any special treatments, for all four patients.