Double bipolar configuration for atrial fibrillation annotation
Catheterization of the heart is carried out by inserting a probe having electrodes into a heart of a living subject, recording a bipolar electrogram and a unipolar electrogram from one of the electrodes at a location in the heart, and defining a window of interest wherein a rate of change in a potential of the bipolar electrogram exceeds a predetermined value. An annotation is established in the unipolar electrogram, wherein the annotation denotes a maximum rate of change in a potential of the unipolar electrogram within the window of interest. A quality value is assigned to the annotation, and a 3-dimensional map is generated of a portion of the heart that includes the annotation and the quality value thereof.
1. A method of removing an interfering signal from a unipolar fibrillation signal, the method comprising:
receiving a first unipolar electrogram and a second unipolar electrogram;
generating a mean QRS template;
subtracting the mean QRS template from the first unipolar electrogram to obtain a first resulting unipolar electrogram;
subtracting the mean QRS template from the second unipolar electrogram to obtain a second resulting unipolar electrogram; and
generating a bipolar electrogram by subtracting the first resulting unipolar electrogram from the resulting second unipolar electrogram.
2. The method of claim 1 , wherein the generating a mean QRS template step further comprises:
identifying plurality of occurrences of QRS episodes in the unipolar electrograms;
identifying a mean of the plurality of QRS episodes; and
generating the mean QRS template from the mean of the plurality of QRS episodes.
3. The method of claim 1 , wherein the generating a mean QRS template step further comprises generating a mean QRS template from a predefined ventricle signal.
4. The method of claim 1 , wherein the generating a mean QRS template step further comprises estimating a ventricular far field signal from a fibrillation signal at times where the signal is only ventricular.
5. The method of claim 1 , further comprising:
identifying a plurality of occurrences of QRS episodes for each of the unipolar electrograms from one or more of a body ECG signal, a ventricular intra-cardiac signal, or a coronary sinus signal.
6. The method of claim 1 , wherein each subtracting step comprises:
identifying times for each occurrence of a plurality of QRS episodes in each of the unipolar electrograms;
subtracting the mean QRS template from the first or second unipolar electrogram at the time identified for each occurrence of a plurality of QRS episodes of the first or second unipolar electrogram.