A system for atrial focal source detection, the system comprising a plurality of sensors (208, 210) configured to detect a plurality of electro-cardiogram signals each indicating electrical activity of a heart over time, each of the plurality of sensors configured to detect one of the ECG signals; a processing device comprising one or more processors configured to: determine, for each of the plurality of ECG signals, one or more local activation times (LATs) each indicating a time of activation of a corresponding ECG signal; and detect whether one or more focal source areas of activation in the heart is indicated based on the detected ECG signals and the one or more local LATs, wherein the one or more processors is further configured to: generate, based on the detected one or more focal source areas of activation, mapping information of the detected one or more focal source areas of activation in the heart; and provide the mapping information for one or more maps representing at least one of the electrical activity of the heart and the spatio-temporal manifestation of the electrical activity of the heart, characterized in that the one or more processors is further configured to provide the mapping information by visually indicating, for each sensor, a level of incidence of the atrial activations occurring before atrial activations of neighboring sensors within a period of time. a plurality of sensors (208, 210) configured to detect a plurality of electro-cardiogram signals each indicating electrical activity of a heart over time, each of the plurality of sensors configured to detect one of the ECG signals; a processing device comprising one or more processors configured to: determine, for each of the plurality of ECG signals, one or more local activation times (LATs) each indicating a time of activation of a corresponding ECG signal; and detect whether one or more focal source areas of activation in the heart is indicated based on the detected ECG signals and the one or more local LATs, wherein the one or more processors is further configured to: generate, based on the detected one or more focal source areas of activation, mapping information of the detected one or more focal source areas of activation in the heart; and provide the mapping information for one or more maps representing at least one of the electrical activity of the heart and the spatio-temporal manifestation of the electrical activity of the heart, characterized in that the one or more processors is further configured to provide the mapping information by visually indicating, for each sensor, a level of incidence of the atrial activations occurring before atrial activations of neighboring sensors within a period of time. determine, for each of the plurality of ECG signals, one or more local activation times (LATs) each indicating a time of activation of a corresponding ECG signal; and detect whether one or more focal source areas of activation in the heart is indicated based on the detected ECG signals and the one or more local LATs, wherein the one or more processors is further configured to: generate, based on the detected one or more focal source areas of activation, mapping information of the detected one or more focal source areas of activation in the heart; and provide the mapping information for one or more maps representing at least one of the electrical activity of the heart and the spatio-temporal manifestation of the electrical activity of the heart, characterized in that the one or more processors is further configured to provide the mapping information by visually indicating, for each sensor, a level of incidence of the atrial activations occurring before atrial activations of neighboring sensors within a period of time. generate, based on the detected one or more focal source areas of activation, mapping information of the detected one or more focal source areas of activation in the heart; and provide the mapping information for one or more maps representing at least one of the electrical activity of the heart and the spatio-temporal manifestation of the electrical activity of the heart, characterized in that the one or more processors is further configured to provide the mapping information by visually indicating, for each sensor, a level of incidence of the atrial activations occurring before atrial activations of neighboring sensors within a period of time.