Locating Equivalent Cardiac Electrical Activity from ECG for Preliminary Diagnosis

摘要

A PC -based method is proposed to enhance the clinical usefulness of the standard 12-lead electrocardiograph of an individual by providing clinicians a fast, simulated, 3-D color image of possible broad locations of the QRS electrical cardiac activity, generating the electrode potentials. The approach consists of placing three rotating, equivalent electrical dipoles within a realistic finite-element model of a human torso: one in the bundle of hiss, and the other two at the center of the left and right ventricles. An optimization is performed of the temporal values of the dipole moments by minimizing the squared difference between an assumed linear function for the electrode potentials, and the precordial lead measurements. The values of the dipole moments are then placed within the FE torso model to generate color-coded potential intensities on the torso and on the pericardium for 3-D visualization. The QRS complex on the precordial leads was chosen because of its high SNR from electrical activity arising primarily from the septum, front, and back sides of the ventricles. The long term objective of this pilot study is to use a 128- electrode system to obtain mathematically-sufficient measurements to support the representation of equivalent, cardiac electrical activity with a much larger set of fixed, as well as, moving and rotating dipole sources, over the complete cardiac cycle. It is expected that the information thus obtained will have the capability of making available to the emergency clinician a non- invasive, inexpensive, and fast tool for preliminary assessments of cardiac anomalies. Tests on a database of 200, 12-lead, normal and arrhythmic ECGs are currently being performed, with expected results to be presented at the Conference.