A system and method of determining regions of interest for heart ablation using fractionation. The method can comprise detecting, via sensors, electrocardiogram (ECG) signals, each ECG signal detected via one of the sensors and indicating electrical activity of a heart, determining, for each of the ECG signals, activation times (LATs) each indicating a time of activation of a corresponding ECG signal, generating, based on the determined LATs of each of the ECG signals, one or more driver maps and one or more perpetuator maps, each representing the electrical activity of the heart, deriving parameters from the driver and perpetuator maps, using at least fractionation, processing and combining the derived parameters into driver evidence and perpetuator evidence, and determining the regions of interest for heart ablation in accordance with the fractionation used to derive the driver evidence and the perpetuator evidence.
