Cardio mapping system and method for cardio mapping

摘要

A method and system for determining the mechanism of cardiac arrhythmia in a patient is disclosed. The method basically entails measuring the impedance of cardiac tissue in a portion of the patient's heart using a catheter during an episode of supraventricular tachycardia to produce an iso-impedance map of that cardiac tissue on a video display and analyzing the pattern of the iso-impedance map to differentiate focal arrhythmia caused by a circumscribed region of focal firing and reentrant arrhythmia caused by a macroreentrant circuit. The method can also be used to identify regions of coherent rapidly conducting tissue e.g., Bachman's bundle or the inferoposterior pathway insertion points, to identify focal “mother rotors” throughout the left atrium that may participate in the generation and maintenance of atrial fibrillation and to identify areas of CAFE (complex atrial/fractionated electrograms) that truly reflect these mother rotors.

主权项

1. A cardiac arrhythmia discrimination system for determining the mechanism of cardiac arrhythmia in a patient, said cardiac arrhythmia discrimination system comprising a catheter and a processor, said system being arranged to measure the impedance of cardiac tissue of the patient at various selected points on the patient's heart during a spontaneously occurring or induced arrhythmia and providing the geometric position of each of said points on the patient's heart, and wherein each of said measurements and positions are arranged to be recorded and analyzed by said processor to determine if a point on the patient's heart exhibits low impedance (Zlow), wherein Zlow≦Zmin+0.1(Zmax−Zmin), where Zmin is the minimum impedance measured and Zmax is the maximum impedance measured, said processor being arranged to discard from its impedance measurements any points associated with tissue voltage of less than a minimum voltage or poor contact of the catheter to the cardiac tissue and impedance measurements from mapping points that are too internal to the anatomic shell or points with far-field low amplitude electrograms, and evaluating the remaining points of measured impedance to determine if there is an area of a predetermined size or predetermined percentage of the atrial surface area having plural Zlow points therein.