Methods, apparatus, and systems for medical procedures are disclosed herein and include receiving a first electrical activity at a first time for a plurality of points on an intrabody surface. A first cluster of points is identified from the plurality of points, based on the first electrical activity, the first cluster of points each exhibiting electrical activity above an activity threshold. A second electrical activity is received at a second time for the plurality of points on the intra-body surface. A second cluster of points is identified from the plurality of points, based on the second electrical activity. The first cluster of points and the second cluster of points are determined to be related based on a propagation threshold. A first visual indication for a first propagation route is provided from the first cluster of points to the second cluster of points.