A method for display, consisting of acquiring an electrical signal from a heart of a subject over multiple heart cycles. The electrical signal is partitioned into a succession of synchronized segments having respective start times at a selected annotation point in the heart cycles. The method includes overlaying respective graphical representations of the synchronized segments in the succession on a display screen, such that each segment is first presented on the display screen with an initial display intensity at a respective display time corresponding to a respective start time of the segment. The method further includes gradually decreasing a display intensity of each segment overlaid on the display screen as a decaying function of a time elapsed since the respective display time.