The visualization of the cardiac excitation spread at a microscopic size scale with a one-dimensional sensor array fabricated in thin-film technique

At a microscopic scale, heart tissue has a structure which represents recurrent electrical discontinuities. This should be reflected in nonuniform conduction within a spatial range of cell dimensions. We used thin-film electrode-arrays with electrode-spacings less than a cell length to obtain datasets of extracellular signals at the surface of in-vitro heart preparations of Guinea pigs. A visualization technique is described, which allows one to trace the spatial course of the local conduction velocities as well as a qualitative visual estimation of the degree of discontinuity of the depolarizing wavefront within a measuring area of 1.2 mm. Signal-density-plots of experimental data and of computer-simulations, taking into account cellular structures, gave similar results