A method includes acquiring a bipolar signal from a first electrode and a second electrode contacting a first location and a second location, respectively, in a heart of a living subject. The method further includes acquiring a unipolar signal from the first electrode while in contact with the first location, and deriving from the bipolar signal and the unipolar signal a point in time at which the first location is generating the unipolar signal. The method also includes computing a metric for a conduction velocity of the unipolar signal at the first location based on a shape of the unipolar signal at the point in time.