A method of determining target heart ablation regions is provided which includes detecting electro-cardiogram (ECG) signals each indicating an electrical activity of a heart over time and determining, for each of the ECG signals, local activation times (LATs) each indicating a time of electrical activation for an area the heart. The method also includes generating, based on the LATs, electrical activity mapping information for displaying one or more maps representing the electrical activity of the heart and alternatively, or in addition to the electrical activity mapping information, generating spatio-temporal mapping information for one or more maps representing a spatio-temporal manifestation of the conditions indicative of cardiac arrhythmia, such as atrial fibrillation (AF). The method further includes determining a region of interest (ROI) of the heart by identifying the ROI as a region exhibiting conditions indicative of cardiac arrhythmia based on the mapping information.