Abstract
Electrograms recorded with a local coaxial reference offer advantages over bipolar electrograms for activation mapping but require more electrodes. We demonstrate that these coaxial electrograms can be recorded with a triangular local reference that can be efficiently created using hexagonal multielectrode grids. Triangular and cross-shaped local references recorded with a custom multielectrode were virtually indistinguishable. In contrast to bipolar electrograms, the morphology of the coaxial electrograms was insensitive to electrode orientation relative to the activation front, and the activation time matched closely with local activation. Developing hexagonal multielectrode designs may improve the efficiency and precision of clinical activation mapping.