Abstract: A method includes receiving a cardiac signal that is sensed by electrodes at a location in a heart of a patient, the cardiac signal including signal components evoked by respective activations. The signal components in the cardiac signal are found and annotated. Respective time differences are calculated between the annotations and the corresponding activations. Based on the time differences, one or more cardiac tissue locations are identified, that demonstrate progressively slowing activation (PSA). An EP map of at least a portion of the heart is presented to a user, including providing a graphical indication of the one or more tissue locations that demonstrate the PSA.

Abstract: A system and method for non-invasively detecting abnormal electrical propagation in the heart are disclosed. The system and method include an interface for receiving a pacing signal applied to a heart of a patient, the pacing signal comprising (i) a sequence of regular pacing stimuli shorter than the sinus-rate intervals, and (ii) one or more extra pacing stimuli at intervals that are shorter than the regular pacing stimuli, a processor to assess the envelope of a body-surface ECG component after the regular pacing stimuli, assess the envelope of a body surface ECG component after the one or more extra pacing stimuli, and compare the assessed component after the extra pacing stimuli to the assessed component after the regular pacing stimuli. The interface outputting the comparison as an indication of regions of arrhythmogenicity and ablation targets in the heart.