Identification and visualization of gaps between cardiac ablation sites

1. A method, comprising:

receiving locations of multiple ablation sites formed on a surface of a heart;

measuring distances among at least some of the ablation sites based on the locations;

based on the distances, determining a second ablation site that is a closest neighbor to a first ablation site;

identifying a gap between the first and second ablation sites and;

determining whether the gap that meets an alerting criterion; and

indicating the identified gap to an operator;

wherein when the gap is determined to meet the alerting criterion, the step of indicating comprises highlighting to the operator that the identified gap is a gap that has been determined to meet the alerting criterion.

2. The method according to claim 1 , wherein the step of determining whether the gap meets an alerting criterion comprises identifying whether the gap is larger than a first threshold but smaller than a second threshold;

wherein when the gap is determined to be larger than a first threshold but smaller than the second threshold, the step of indicating comprises highlighting to the operator that the identified gap is a gap that has been determined to meet the alerting criterion.

3. The method according to claim 1 , wherein measuring the distances comprises scaling a distance between the first and second ablation sites by a scaling factor that depends on an ablation quality associated with one or both of the first and second ablation sites.

4. The method according to claim 1 , wherein measuring the distances comprises clustering the ablation sites into groups by connecting adjacent ablation sites whose distances are smaller than a first threshold, and wherein the step of determining whether the gap meets an alerting criterion comprises identifying separations between at least a first group comprising the first ablation site and a second group comprising the second ablation site that are smaller than a second threshold.

5. The method according to claim 4 , wherein clustering the ablation sites comprises iteratively calculating the distances from a given cluster to one or more of the ablation sites, and adding an ablation site to the given cluster upon finding that a distance from the ablation site to the given cluster is smaller than the first threshold.

6. The method according to claim 1 , wherein measuring the distances comprises assessing the distances depending on parameters of an ablation signal used for forming the ablation sites.

7. The method according to claim 1 , wherein measuring the distances comprises assessing the distances depending on sizes of the ablation sites.

8. The method according to claim 1 , wherein the step of determining whether the gap meets an alerting criterion comprises determining whether the gap is:

(a) smaller than a first threshold;

(b) larger than the first threshold, but smaller than a second threshold; or

(c) larger than the second threshold;

wherein when the gap is determined to be larger than the first threshold but smaller than the second threshold, the step of indicating comprises highlighting to the operator that the identified gap is a gap that has been determined to meet the alerting criterion.

9. The method of claim 8 , wherein when the gap is determined to be less that the first threshold, the step of indicating comprises displaying the first and second ablation sites connected by a line;

wherein when the gap is determined to be larger than the first threshold but smaller than the second threshold, the step of indicating comprises displaying the first and second ablation sites connected by a bold line to highlight to the operator that the identified gap is a gap that has been determined to meet the alerting criterion; and

wherein when the gap is determined to be greater that the second threshold, the step of indicating comprises displaying no connection between the first and second ablation sites.

10. A system, comprising:

an interface, which is configured to receive locations of multiple ablation sites formed on a surface of a heart;

a processor, which is configured to:

measure distances among at least some of the ablation sites based on the locations and to determine a second ablation site that is a closest neighbor to a first ablation site,

to identify a gap between the first and second ablation sites, and

to determine whether the gap meets an alerting criterion; and

a display to indicate the identified gaps to an operator;

wherein when the gap is determined to meet the alerting criterion, the display highlights the gap to the operator to indicate that the identified gap is a gap that has been determined to meet the alerting criterion.

11. The system according to claim 10 , wherein the processor is configured to determine whether the gap meets an alerting criterion by detecting the gaps that are larger than a first threshold but smaller than a second threshold;

wherein when the gap is determined to be larger than a first threshold but smaller than the second threshold, the step of indicating comprises highlighting to the operator that the identified gap is a gap that has been determined to meet the alerting criterion.

12. The system according to claim 10 , wherein the processor is configured to scale a distance between the first and second ablation sites by a scaling factor that depends on an ablation quality associated with one or both of the first and second ablation sites.

13. The system according to claim 10 , wherein the processor is configured to cluster the ablation sites into groups by connecting adjacent ablation sites whose distances are smaller than a first threshold, and to identify separations between at least a first group comprising the first ablation site and a second group comprising the second ablation site that are smaller than a second threshold.

14. The system according to claim 13 , wherein the processor is configured to cluster the ablation sites by iteratively calculating the distances from a given cluster to one or more of the ablation sites, and adding an ablation site to the given cluster upon finding that a distance from the ablation site to the given cluster is smaller than the first threshold.

15. The system according to claim 10 , wherein the processor is configured to assess the distances depending on parameters of an ablation signal used for forming the ablation sites.

16. The system according to claim 10 , wherein the processor is configured to assess the distances depending on sizes of the ablation sites.

17. The system according to claim 10 , wherein to determine whether the gap meets an alerting criterion the processor is configured to determine whether the gap is:

(a) smaller than a first threshold;

(b) larger than the first threshold, but smaller than a second threshold; or

(c) larger than the second threshold;

wherein when the gap is determined to be larger than the first threshold but smaller than the second threshold, the display highlights to the operator that the identified gap is a gap that has been determined to meet the alerting criterion.

18. The system of claim 17 , wherein when the gap is determined to be less that the first threshold, the display indicates the first and second ablation sites connected by a line;

wherein when the gap is determined to be larger than the first threshold but smaller than the second threshold, the display indicates the first and second ablation sites connected by a bold line to highlight to the operator that the identified gap is a gap that has been determined to meet the alerting criterion; and

wherein when the gap is determined to be greater that the second threshold, the display indicates no connection between the first and second ablation sites.