Ep Technologies, Inc.

University of Pennsylvania

The Catholic University of America

Philadelphia Heart Institute

Other

David S Schwartzman

Mark S Mirotznik

Kenneth R Foster

David K Swanson

Dorin Panescu

Francis E Marchlinski

Isaac Chang

Charles D Gottlieb

Dorin Nmi Panescu

Charles D Gottleb

Systems and methods examine heart tissue morphology using three or more spaced apart electrodes, at least two of which are located within the heart in contact with endocardial tissue. The systems and methods transmit electrical current through a region of heart tissue lying between selected pairs of the electrodes, at least one of the electrodes in each pair being located within the heart. The systems and methods derive the electrical characteristic of tissue lying between the electrode pairs based, at least in part, upon sensing tissue impedances. The systems and methods make possible the use of multiple endocardial electrodes for taking multiple measurements of the electrical characteristics of heart tissue. Multiplexing can be used to facilitate data processing. The systems and methods also make possible the identification of regions of low relative electrical characteristics, indicative of infarcted tissue, without invasive surgical techniques.

Systems and methods for examining the electrical characteristic of cardiac tissue

A method of locating infarcted myocardial tissue in a beating heart includes the step of inserting an impedance measuring tip of a catheter into the chamber of the beating heart, particularly the left or right ventricle, and measuring the impedance of the endocardium at various locations within the chamber of the beating heart. The values measured are compared to impedance values with a predetermined range of values to identify an infarcted area of myocardium and distinguish such area from normal myocardium. The measurements are also compared to a range of values for an infarction border zone. In accordance with the invention, the infarction border zone may be located. The infarction border zone is a significant source of arrhythmia, and particularly of ventricular tachycardia. Further, in accordance with the methods of the present invention, the risk of arrhythmia in a beating heart may be substantially reduced or eliminated by ablating endocardium within the infarction border zone utilizing the same catheter tip. Impedance measurements may also be utilized to assess the adequacy of the electrode-tissue contact, particularly in a fluid filled body organ or cavity. Further, the effectiveness of the ablation of the tissue may be determined by determining the degree of heating of the tissue by measuring the change in impedance in the area of ablation.

Method of using endocardial impedance for determining electrode-tissue

Systems and methods examine heart tissue morphology using a pair of electrodes, at least one of which is located in contact with heart tissue. The systems and methods transmit electrical current in a path through the contacted heart tissue between the pair of the electrodes to derive a tissue electrical characteristic based, at least in part, upon sensing the impedance of the tissue lying in the path. The system and methods also sense with at least one of the electrodes the timing of local depolarization events in the contacted heart tissue. The systems and methods make possible the use of multiple endocardial electrodes for taking multiple measurements of the electrical characteristics of heart tissue. Multiplexing can be used to facilitate data processing. The systems and methods also make possible the identification of regions of low relative electrical characteristics, indicative of infarcted tissue, without invasive surgical techniques.

Systems and methods for examining the electrical characteristics and

Method of using endocardial impedance for assessing tissue heating

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Philadelphia, PA, United States of America

David S Schwartzman