Abstract: An electrode catheter is provided for ablation of arrhythmogenic tissue in a malperforming heart and includes an elongated catheter tube having longitudinally spaced apart proximal and distal ends. At least one electrode for ablation of the arrhythmogenic tissue in a targeted region of the patient is carried on the catheter tube, preferable at or proximate the distal end of the catheter tube. One such electrode may be located at the distal tip of the catheter and configured in the shape of a generally flat disk that substantially conforms to the contour of the targeted region and such that the ratio of the surface area of the tissue-contacting end face to that of a side wall portion of the electrode is greater than 1.0.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.