A post-processing method of mapping electrophysiological activity, comprising: receiving, at an electroanatomical mapping system, a plurality of electrophysiological signals collected during an electrophysiology study performed at an earlier time, wherein each electrophysiological signal comprises an omnipolar signal and spans an activation interval, wherein the omnipolar signal is defined by two or more bipolar signals orthogonal to each other; and for each previously received electrophysiological signal of the plurality of electrophysiological signals, the electroanatomical mapping system: identifying an initial event time within the activation interval of the electrophysiological signal; defining a sub-interval, shorter in duration than the activation interval, about the initial event time; analyzing only the sub-interval to identify one or more electrophysiological characteristics of the electrophysiological signal; and adding an electrophysiology data point to an electrophysiology map, wherein the electrophysiology data point includes the one or more electrophysiological characteristics of the electrophysiological signal associated with a location at which the electrophysiological signal was measured, wherein the omnipolar signal comprises an omnipolar electrogram defined by at least two bipolar electrograms (602, 604), and wherein identifying an initial event time within the activation interval of the electrophysiological signal comprises computing root mean squares of derivatives of the at least two bipolar electrograms (602, 604) to identify the initial event time, or wherein identifying an initial event time within the activation interval of the electrophysiological signal comprises computing a mean absolute value transform of derivatives of the at least two bipolar electrograms (602, 604) to identify the initial event time. receiving, at an electroanatomical mapping system, a plurality of electrophysiological signals collected during an electrophysiology study performed at an earlier time, wherein each electrophysiological signal comprises an omnipolar signal and spans an activation interval, wherein the omnipolar signal is defined by two or more bipolar signals orthogonal to each other; and for each previously received electrophysiological signal of the plurality of electrophysiological signals, the electroanatomical mapping system: identifying an initial event time within the activation interval of the electrophysiological signal; defining a sub-interval, shorter in duration than the activation interval, about the initial event time; analyzing only the sub-interval to identify one or more electrophysiological characteristics of the electrophysiological signal; and adding an electrophysiology data point to an electrophysiology map, wherein the electrophysiology data point includes the one or more electrophysiological characteristics of the electrophysiological signal associated with a location at which the electrophysiological signal was measured, identifying an initial event time within the activation interval of the electrophysiological signal; defining a sub-interval, shorter in duration than the activation interval, about the initial event time; analyzing only the sub-interval to identify one or more electrophysiological characteristics of the electrophysiological signal; and adding an electrophysiology data point to an electrophysiology map, wherein the electrophysiology data point includes the one or more electrophysiological characteristics of the electrophysiological signal associated with a location at which the electrophysiological signal was measured, wherein the omnipolar signal comprises an omnipolar electrogram defined by at least two bipolar electrograms (602, 604), and wherein identifying an initial event time within the activation interval of the electrophysiological signal comprises computing root mean squares of derivatives of the at least two bipolar electrograms (602, 604) to identify the initial event time, or wherein identifying an initial event time within the activation interval of the electrophysiological signal comprises computing a mean absolute value transform of derivatives of the at least two bipolar electrograms (602, 604) to identify the initial event time.