Value and limitations of an inverse solution for two equivalent dipoles in localising dual accessory pathways

Investigations were carried out into whether an equivalent generator consisting of two dipoles could be used to detect dual sites of ventricular activity. A computer model of the human ventricular myocardium was used to simulate activation sequences initiated at eight different pairs of sites positioned on the epicardial surface of the atrio-ventricular ring. From these sequences, 117-lead body surface potentials (covering the anterior and posterior torso), 64-lead magnetic field maps (above the anterior chest) and 128-lead magnetic field maps (above the anterior and posterior chest) were simulated and were then used to localise dual accessory pathways employing pairs of equivalent dipoles. Average localisation errors were 12 mm, 12mm and 9mm, respectively, when body surface potentials, 64-lead and 128-lead magnetic fields were used. The results of the study suggest that solving the inverse problem for two dipoles could provide additional information on dual accessory pathways prior to electrophysiological study.

[1]  Non-invasive imaging of epicardial electrograms during controlled myocardial ischemia , 2000, Computers in Cardiology 2000. Vol.27 (Cat. 00CH37163).

[2]  G. Stroink,et al.  Magnetocardiographic functional localization using a current dipole in a realistic torso , 1991, IEEE Transactions on Biomedical Engineering.

[3]  B.M. Horacek,et al.  Body surface mapping for localization of accessory pathways in WPW syndrome , 1992, Proceedings Computers in Cardiology.

[4]  B. M. Horacek,et al.  Numerical Model of an Inhomogeneous Human Torso1 , 1974 .

[5]  B. M. Horáček,et al.  Accuracy of single-dipole inverse solution when localising ventricular pre-excitation sites: simulation study , 1998, Medical and Biological Engineering and Computing.

[6]  B M Horácek,et al.  Computer model of excitation and recovery in the anisotropic myocardium. II. Excitation in the simplified left ventricle. , 1991, Journal of electrocardiology.

[7]  J.C. Mosher,et al.  Multiple dipole modeling and localization from spatio-temporal MEG data , 1992, IEEE Transactions on Biomedical Engineering.

[8]  Jyrki Lötjönen,et al.  Reconstruction of 3-D geometry using 2-D profiles and a geometric prior model , 1999, IEEE Transactions on Medical Imaging.

[9]  R. Lux,et al.  Effect of Myocardial Fiber Direction on Epicardial Potentials , 1994, Circulation.

[10]  B M Horácek,et al.  Computer model of excitation and recovery in the anisotropic myocardium. I. Rectangular and cubic arrays of excitable elements. , 1991, Journal of electrocardiology.

[11]  Y. Rudy,et al.  Electrocardiographic Imaging: II. Effect of Torso Inhomogeneities on Noninvasive Reconstruction of Epicardial Potentials, Electrograms, and Isochrones , 2001, Journal of cardiovascular electrophysiology.

[12]  G. Stroink,et al.  Moving dipole inverse solutions using realistic torso models , 1991, IEEE Transactions on Biomedical Engineering.

[13]  D. Marquardt.  An Algorithm for Least-Squares Estimation of Nonlinear Parameters , 1963 .

[14]  B. Horáček,et al.  The inverse problem of electrocardiography: a solution in terms of single- and double-layer sources of the epicardial surface. , 1997, Mathematical biosciences.

[15]  J. Nenonen,et al.  Computer model of propagated excitation in the anisotropic human heart. I. Implementation and algorithms , 1991, [1991] Proceedings Computers in Cardiology.

[16]  F. Roberge,et al.  Moving Dipole Inverse ECG and EEG Solutions , 1984, IEEE Transactions on Biomedical Engineering.

[17]  Amanda L. Kaas,et al.  A fast method to derive realistic BEM models for E/MEG source reconstruction , 2001, IEEE Trans. Biomed. Eng..

[18]  R. Hren,et al.  Noninvasive characterisation of multiple ventricular events using electrocardiographic imaging , 2006, Medical and Biological Engineering and Computing.

[19]  A. van Oosterom,et al.  Source parameter estimation in inhomogeneous volume conductors of arbitrary shape , 1989, IEEE Transactions on Biomedical Engineering.

[20]  M. Scheinman,et al.  Interventional electrophysiology. , 1983, Mayo Clinic proceedings.

[21]  Y. Rudy,et al.  Electrocardiographic Imaging: I. Effect of Torso Inhomogeneities on Body Surface Electrocardiographic Potentials , 2001, Journal of cardiovascular electrophysiology.

[22]  F. Roberge,et al.  Inverse Recovery of Two Moving Dipoles from Simulated Surface Potential Distributions on a Realistic Human Torso Model , 1985, IEEE Transactions on Biomedical Engineering.

[23]  Robert Guardo,et al.  A Simulation Study of the Single Moving Dipole Representation of Cardiac Electrical Activity , 1982, IEEE Transactions on Biomedical Engineering.

[24]  Y. Rudy,et al.  Noninvasive Electrocardiographic Imaging , 1999 .

[25]  Y. Rudy,et al.  Noninvasive electrocardiographic imaging: reconstruction of epicardial potentials, electrograms, and isochrones and localization of single and multiple electrocardiac events. , 1997, Circulation.

[26]  R Trobec,et al.  Computer simulation and spatial modelling in heart surgery. , 1998, Computers in biology and medicine.

[27]  G. Stroink,et al.  Spatial resolution of body surface potential maps and magnetic field maps: A simulation study applied to the identification of ventricular pre-excitation sites , 1998, Medical and Biological Engineering and Computing.