Method and system for measuring cardiac tissue health based on DV/DTMIN of a depolarization wave within a cardiac electrogram

1. A method for determining cardiac tissue health based on a depolarization wave within an electrogram (EGM), comprising:

measuring the EGM as a voltage signal using one or more catheters;

computing a derivative signal as a first derivative of the EGM with respect to time (DV/DT);

determining extrema for the derivative signal;

establishing a value DV/DT MIN as a minimum value of the derivative signal, based on the extrema; and

mapping the value DV/DT MIN to cardiac tissue.

2. The method of claim 1 , when the electrogram comprises a unipolar electrogram, then establishing the value DV/DT MIN comprises selecting a minima from the extrema as the value for DV/DT MIN .

3. The method of claim 1 , when the electrogram comprises a bipolar electrogram, then establishing the value DV/DT MIN comprises selecting as one of a maxima and a minima from the extrema as the value for DV/DT MIN N based on a ratio.

4. The method of claim 3 , wherein the value for DV/DT MIN is selected as Min dV/dt when the ratio |Min dV/dt|/|Max dV/dt| is greater than or equal to one.

5. The method of claim 3 , wherein the value for DV/DT MIN is selected as the—Max dV/dt when the ratio |Min dV/dt|/|Max dV/dt| is less than one.

6. A system for determining cardiac tissue health based on a depolarization wave within an electrogram (EGM), comprising:

a signal acquisition module to measure the EGM as a voltage signal;

one or more processors coupled to a memory programmed with executable instructions to:

compute a derivative signal as a first derivative of the EGM with respect to time (DV/DT);

determine extrema for the derivative signal;

establish a value DV/DT MIN as a minimum value of the derivative signal, based on the extrema;

map the value DV/DT MIN to cardiac tissue.

7. The system of claim 6 , when the electrogram comprises a unipolar electrogram, then the value of DV/DT MIN is established by selecting a minima from the extrema as the value for DV/DT MIN .

8. The system of claim 6 , when the electrogram comprises a bipolar electrogram, then the value DV/DT MIN is established by selecting as one of a maxima and a minima from the extrema as the value for DV/DT MIN based on a ratio.

9. The system of claim 8 , wherein the value for DV/DT MIN is selected as Min dV/dt when the ratio |Min dV/dt|/|Max dV/dt| is greater than or equal to one.

10. The system of claim 8 , wherein the value for DV/DT MIN is selected as the—Max dV/dt when the ratio |Min dV/dt|/|Max dV/dt| is less than one.

11. A non-transitory computer readable storage medium, having stored thereon, a set of computer-executable instructions that causes a computer to perform the method comprising:

measuring an electrogram (EGM) as a voltage signal using one or more catheters;

computing a derivative signal as a first derivative of the EGM with respect to time (DV/DT);

determining extrema for the derivative signal;

establishing a value DV/DT MIN as a minimum value of the derivative signal, based on the extrema; and

mapping the value DV/DT MIN to cardiac tissue.

12. The non-transitory computer readable storage medium of claim 11 , when the electrogram comprises a unipolar electrogram, then establishing the value DV/DT MIN comprises selecting a minima from the extrema as the value for DV/DT MIN .

13. The non-transitory computer readable storage medium of claim 11 , when the electrogram comprises a bipolar electrogram, then establishing the value DV/DT MIN comprises selecting as one of a maxima and a minima from the extrema as the value for DV/DT MIN based on a ratio.

14. The non-transitory computer readable storage medium of claim 13 , wherein the value for DV/DT MIN is selected as Min dV/dt when the ratio |Min dV/dt|/|Max dV/dt| is greater than or equal to one.

15. The non-transitory computer readable storage medium of claim 13 , wherein the value for DV/DT MIN is selected as the—Max dV/dt when the ratio |Min dV/dt|/|Max dV/dt| is less than one.