Fig. 1.

a Posterior part of the lower right atrium of a Rabbit heart (ROI region of interest) pinned on silicone rubber with tungsten needles and superfused with oxygenated Tyrode’s solution. b Ramification of the terminal crest into a pectinate muscle. Two four-electrode sensor arrays carried from flexible polyamide to measure extracellular potentials are shown. c Finite element model of a thin-walled cardiac sample, resembling the pectinate in b, immersed in a bath with four symmetrically arranged grounding electrodes