Advances in inverse electrocardiography based imaging: from simple models to clinical applications

Introduction: A long-term priority of contemporary biomedicine is the problem of ischemic heart disease. The aim of our investigation was to study, with the use of mathematical and computer models, the tendencies of variation of the morphological characteristics of the T wave of the ECG following a change of parameters of the transmembrane action potential in an “ischemic” zone with evaluation of the possible use of the results in computer based diagnostic algorithms. Methods: Computer experiments were executed on a system for 3D-modeling of the cardiac electrical activity with the aid of our earlier developed model of ECG genesis (cellular automaton of about a million elements of the Myocardium-His-Purkinje type), the parameters of which are electrophysiological, anatomical, and biophysical characteristics of heart muscle. Processing of the model ECG was carried out with our special program. Results: Methods of segmentation of the model hearts on separate compartments (segments), as well as calculation and visualization of the partial contribution of any segment into the potential of the chosen lead against a background of the summary ECG have been developed and were used in the given work. For the modeled cardiosignals, some «medical» evaluation in terms of the Minnesota Code has been carried out and a set of characteristics, similar to parameters of the real ECG, has been measured and calculated. The most sensitive parameters of “ECG” for ischemia have been selected and analysed. Conclusion: Systematic comparative investigations on the basis of modeling ischemia of various localization, extensiveness and degree of intensity are necessary. In conclusion, it should also be noted that the method of phase space is far from having exhausted itself and, as a preliminary consideration, may be developed into an n-dimensional area during a search for a complex of informative parameters for new diagnostic algorithms.