ENDOCARDIAL POTENTIAL MAPPING FROM A NONCONTACT NONEXPANDABLE CATHETER - A FEASIBILITY STUDY

In previous studies, we established methodology for reconstructing end ocardial potentials, electrograms and isochrones from a non-contact in tracavitary probe during a single beat. The probe was too large to be introduced percutaneously. Here we examine the possibility of similar mapping with a small multielectrode catheter that could be introduced percutaneously and does not expand inside the cavity. Cavity geometry and endocardial potentials were recorded in an isolated canine left ve ntricle. Simulated catheter probes were introduced into the cavity. Pr obe potentials were computed from the measured endocardial potentials and perturbed to include measurement noise, geometrical errors, and li mited electrode density. Endocardial potentials were then reconstructe d from the perturbed probe potentials and compared to the actual measu red potentials. Of all probes simulated, a 3.0 mn (9F) catheter that a ssumes a curved geometry (e.g., a J shape) inside the cavity performed best (better than a larger 7.6 mm cylinder simulating an inflatable p robe). Without bending, a straight cylindrical probe of the same size (9F, 3.0 mm) did not perform well. Sixty probe electrodes were needed for accurate reconstruction. The J-probe reconstruction was very robus t in the presence of noise (10%) and of geometry errors (3 mm shift, 1 0 degrees rotation). The results demonstrate the feasibility of accura te single-beat endocardial mapping using a 9F percutaneous multielectr ode catheter that assumes a J shape in the cavity without the need for expansion (e.g., into a balloon or a ''basket''). The robustness of t he procedure to noise and geometrical errors suggests its applicabilit y in the clinical EP laboratory and the possibility of determining pro be position in vivo using current imaging modalities. (C) 1998 Biomedi cal Engineering Society. [S0090-6964(98)00406-8].