VENTRICULAR FAR FIELD REDUCTION

摘要

Far field reduction is carried out in a cardiac electrogram by extracting unipolar beats of an intracardiac electrogram that occur within a predetermined time interval that includes QRS peaks, constructing a first mean unipolar beat by averaging the extracted unipolar beats, and accepting unipolar beats that cross-correlate with the first mean unipolar beat. A second mean unipolar beat is constructed from the accepted unipolar beats. A ventricular far field component is determined from the extracted unipolar beats and subtracted from the intracardiac electrogram to distinguish a local component of the intracardiac electrogram.

主权项

1. A method of far field reduction, comprising the steps of detecting peaks of a QRS complex of a cardiac electrogram;
extracting unipolar beats of an intracardiac electrogram that occur within a predetermined time interval that includes respective detected peaks; constructing a first mean unipolar beat by averaging the extracted unipolar beats; cross correlating the extracted unipolar beats with the first mean unipolar beat by determining respective time-lags therebetween; accepting ones of the extracted unipolar beats wherein a cross correlation thereof exceeds a predetermined correlation threshold; constructing a second mean unipolar beat from the accepted unipolar beats; determining a ventricular far field component by subtracting the second mean unipolar beat from the extracted unipolar beats; subtracting the ventricular far field component from the intracardiac electrogram to distinguish a local component of the intracardiac electrogram; and controlling a medical procedure responsively to the local component.