Apparatus for electrophysiological assessment, comprising: a display, configured to present an electroanatomical map of a heart; a probe, configured to acquire electrical signals from myocardial tissue at multiple locations in a vicinity of a region of ablated tissue in a chamber of the heart; a tracking module configured to track the path of the probe in a mapping region containing the heart; and a processor in communication with the tracking module, the processor configured to: record locations of the ablated tissue and illustrate the locations on the electroanatomical map, store the electrical signals, derive from the electrical signals respective annotations, which are indicative of times within a cycle of the heart at which a conduction wave in the myocardial tissue traversed the locations, store the annotations and the locations at which the electrical signals providing them were acquired, identify a first location, at a first distance from the region of the ablated tissue, where the electrical signals comprise a double-potential signal, having a first annotation and a second annotation at different, respective times within the cycle of the heart, identify, in proximity to the first location, a second location, at a second distance from the region of the ablated tissue, greater than the first distance, where the electrical signals have a third annotation, select one of the first annotation and the second annotation that is closest to the third annotation as a valid annotation for the first location, and display the valid annotation on the electroanatomical map of the heart. a display, configured to present an electroanatomical map of a heart; a probe, configured to acquire electrical signals from myocardial tissue at multiple locations in a vicinity of a region of ablated tissue in a chamber of the heart; a tracking module configured to track the path of the probe in a mapping region containing the heart; and a processor in communication with the tracking module, the processor configured to: record locations of the ablated tissue and illustrate the locations on the electroanatomical map, store the electrical signals, derive from the electrical signals respective annotations, which are indicative of times within a cycle of the heart at which a conduction wave in the myocardial tissue traversed the locations, store the annotations and the locations at which the electrical signals providing them were acquired, identify a first location, at a first distance from the region of the ablated tissue, where the electrical signals comprise a double-potential signal, having a first annotation and a second annotation at different, respective times within the cycle of the heart, identify, in proximity to the first location, a second location, at a second distance from the region of the ablated tissue, greater than the first distance, where the electrical signals have a third annotation, select one of the first annotation and the second annotation that is closest to the third annotation as a valid annotation for the first location, and display the valid annotation on the electroanatomical map of the heart. record locations of the ablated tissue and illustrate the locations on the electroanatomical map, store the electrical signals, derive from the electrical signals respective annotations, which are indicative of times within a cycle of the heart at which a conduction wave in the myocardial tissue traversed the locations, store the annotations and the locations at which the electrical signals providing them were acquired, identify a first location, at a first distance from the region of the ablated tissue, where the electrical signals comprise a double-potential signal, having a first annotation and a second annotation at different, respective times within the cycle of the heart, identify, in proximity to the first location, a second location, at a second distance from the region of the ablated tissue, greater than the first distance, where the electrical signals have a third annotation, select one of the first annotation and the second annotation that is closest to the third annotation as a valid annotation for the first location, and display the valid annotation on the electroanatomical map of the heart.