A method of displaying an image of the location of one or more low voltage structures in tissue is provided. The method includes receiving electrical mapping data corresponding to a portion of the tissue. The method further includes generating an image using the electrical mapping data. Electrical mapping values within at least one voltage range having two endpoints that bound the upper and lower limits of the voltage range are distinguishable from electrical mapping values outside the at least one voltage range. The two endpoints are selected to distinguish the one or more low voltage structures of the tissue from other portions of the tissue.