Visually differentiating primary and secondary activations on electrophysiological maps

1. A method for visually differentiating primary and secondary activations on electrophysiological maps, the method comprising:

receiving an anatomical map of at least a portion of a heart;

receiving, for at least a region of the anatomical map, positions and respective bipolar intracardiac electrogram (EGM) signals measured at the positions;

identifying in the bipolar intracardiac EGM signals primary activations and secondary activations, wherein identifying the primary activations and the secondary activations in a bipolar intracardiac EGM signal among the bipolar intracardiac EGM signals comprises:

selecting a noise level for the bipolar intracardiac EGM signal;

labeling local maxima of the bipolar intracardiac EGM signal, which are above the selected noise level, as activations; and

for a given cardiac cycle, visually labeling an activation having a maximum absolute value as a primary activation, and visually labeling other activations as secondary activations both on the anatomical map;

deriving a surface representation of the bipolar intracardiac EGM signals over the region, including the identified primary activations and secondary activations; and

presenting the surface representation overlaid on the anatomical map.

2. The method according to claim 1 , wherein presenting the surface representation comprises presenting the primary activations using a first type of visual indicator and presenting the secondary activations using a second type of visual indicator.

3. The method according to claim 2 , wherein the first and second types of the visual indicators comprise first and second different geometrical shapes.

4. The method according to claim 2 , wherein the first and second types of the visual indicators have first and second different colors.

5. The method according to claim 2 , wherein the first and second types of the visual indicators represent Local Activation Times (LAT).

6. A system for visually differentiating primary and secondary activations on electrophysiological maps, the system comprising:

a memory, which is configured to store an anatomical map of at least a portion of a heart; and

a processor, which is configured to:

receive, for at least a region of the anatomical map, positions and respective bipolar intracardiac electrogram (EGM) signals measured at the positions;

identify in the bipolar intracardiac EGM signals primary activations and secondary activations, wherein the processor is configured to identify the primary activations and the secondary activations in an bipolar intracardiac EGM signal among the bipolar intracardiac EGM signals, by:

selecting a noise level for the bipolar intracardiac EGM signal;

labeling local maxima of the bipolar intracardiac EGM signal, which are above the selected noise level, as activations; and

for a given cardiac cycle, labeling an activation having a maximum absolute value as a primary activation, and labeling other activations as secondary activations both on the anatomical map;

derive a surface representation of the bipolar intracardiac EGM signals over the region, including the identified primary activations and secondary activations; and

present the surface representation overlaid on the anatomical map.

7. The system according to claim 6 , wherein the processor is configured to present the surface representation by presenting the primary activations using a first type of visual indicator and presenting the secondary activations using a second type of visual indicator.

8. The system according to claim 7 , wherein the first and second types of type of the visual indicators comprise first and second different geometrical shapes.

9. The system according to claim 7 , wherein the first and second types of type of the visual indicators have first and second different colors.

10. The system according to claim 7 , wherein the first and second types of the visual indicators represent Local Activation Times (LAT).