SPREAD OF EXCITATION IN 3-D MODELS OF THE ANISOTROPIC CARDIAC TISSUE - III - EFFECTS OF VENTRICULAR GEOMETRY AND FIBER STRUCTURE ON THE POTENTIAL DISTRIBUTION

In a previous paper we studied the spread of excitation in a simplifie d model of the left ventricle, affected by fiber structure and oblique ness, curvature of the wall and Purkinje network. In the present paper we investigate the extracellular potential distribution u in the same ventricular model. Given the transmembrane potential v, associated wi th the spreading excitation, the extracellular potential u is obtained as the solution of a linear elliptic equation with the source term re lated to v. The potential distributions were computed for point stimul ations at different intramural depths. The results of the simulations enabled us to identify a number of common features which appear in all the potential patterns irrespective of pacing site. In addition, by s plitting the sources into an axial and conormal component, we were abl e to evaluate the contribution of the classical uniform dipole layer t o the total potential field and the role of the superimposed axial com ponent. (C) 1998 Elsevier Science Inc, All rights reserved.