An example system and method of reconstructing biological activation information are disclosed. A first biological signal and a second biological signal associated with an organ are processed via a computing device to determine whether there is a point of change in a derivative of the first biological signal with respect to a derivative of the second biological signal above a threshold. An activation onset time is assigned in the first biological signal at the point of change to define biological activation associated with the organ in the first cardiac signal if it is determined that the point of change is above the threshold.
