This document presents a system for managing treatment for an emergency cardiac event. The system includes memory, one or more electronic ports for receiving ECG signals, and a treatment module executable on one or more processing devices. The module is configured to perform a number of transformation on portions of an ECG signal into frequency domain data, obtain one or more previous values derived from one or more time segments of the ECG, and determine, based on the frequency domain data a first value and a second value, determine a probability of therapeutic success. The module is further configured to cause one or more output devices to present an indication of the probability of therapeutic success.