A medical apparatus, comprising: a probe, adapted for insertion into a heart, the probe comprising an elongated body, and a mapping electrode disposed on a distal portion of the body; a memory; a display; and a processor linked to the display and being coupled to access the memory, the processor being connectable to receive an input provided by the mapping electrode, wherein the processor is configured to perform the steps of: obtaining electrocardiographic signals from a target tissue in the heart via the mapping electrode while the mapping electrode is maintained in a contacting relationship with the target tissue; holding a series of the electrocardiographic signals in a buffer; selecting a first signal from the buffer as indicative of a cardiac arrhythmia, the first signal occurring at a first point in time, the mapping electrode being at a first location at the first point in time; selecting a second signal from the buffer as indicative of an absence of the cardiac arrhythmia, the second signal occurring at a second point in time, the mapping electrode being at a second location at the second point in time; assigning electrical data from the electrocardiographic signals obtained at the first location to the second location, wherein the electrical data comprises a local activation time; generating an electroanatomic map based on the assigned electrical data at the second location; and presenting the electroanatomic map on the display, the electroanatomic map showing the first location and the second location. a probe, adapted for insertion into a heart, the probe comprising an elongated body, and a mapping electrode disposed on a distal portion of the body; a memory; a display; and a processor linked to the display and being coupled to access the memory, the processor being connectable to receive an input provided by the mapping electrode, wherein the processor is configured to perform the steps of: obtaining electrocardiographic signals from a target tissue in the heart via the mapping electrode while the mapping electrode is maintained in a contacting relationship with the target tissue; holding a series of the electrocardiographic signals in a buffer; selecting a first signal from the buffer as indicative of a cardiac arrhythmia, the first signal occurring at a first point in time, the mapping electrode being at a first location at the first point in time; selecting a second signal from the buffer as indicative of an absence of the cardiac arrhythmia, the second signal occurring at a second point in time, the mapping electrode being at a second location at the second point in time; assigning electrical data from the electrocardiographic signals obtained at the first location to the second location, wherein the electrical data comprises a local activation time; generating an electroanatomic map based on the assigned electrical data at the second location; and presenting the electroanatomic map on the display, the electroanatomic map showing the first location and the second location. obtaining electrocardiographic signals from a target tissue in the heart via the mapping electrode while the mapping electrode is maintained in a contacting relationship with the target tissue; holding a series of the electrocardiographic signals in a buffer; selecting a first signal from the buffer as indicative of a cardiac arrhythmia, the first signal occurring at a first point in time, the mapping electrode being at a first location at the first point in time; selecting a second signal from the buffer as indicative of an absence of the cardiac arrhythmia, the second signal occurring at a second point in time, the mapping electrode being at a second location at the second point in time; assigning electrical data from the electrocardiographic signals obtained at the first location to the second location, wherein the electrical data comprises a local activation time; generating an electroanatomic map based on the assigned electrical data at the second location; and presenting the electroanatomic map on the display, the electroanatomic map showing the first location and the second location.