Localization of the site of origin of cardiac activation by means of a heart-model-based electrocardiographic imaging approach

We have developed a new approach to solve the inverse problem of electrocar diography in terms of heart model parameters. The inverse solution of the e lectrocardiogram (ECG) inverse problem is defined, in the present study, as the parameters of the heart model, which are closely related to the physio logical and pathophysiological status of the heart, and is estimated by usi ng an optimization system of heart model parameters, instead of solving the matrix equation relating the body surface ECGs and equivalent cardiac sour ces. An artificial neural network based preliminary diagnosis system has be en developed to limit the searching space of the optimization algorithm and to initialize the model parameters in the computer heart model. The optima l heart model parameters were obtained by minimizing the objective function s, as functions of the observed and model-generated body surface ECGs, We h ave tested the feasibility of the newly developed technique in localizing t he site of origin of cardiac: activation using a pace mapping protocol. The present computer simulation results show that, the present approach for lo calization of the site of origin of ventricular activation achieved an aver aged localization error of about 3 mm [for 5-muV Gaussian white noise (GWN) ] and 4 mm (for 10-muV GWN), with standard deviation of the localization er rors of being about 1.5 mm. The present simulation study suggests that this newly developed approach provides a robust inverse solution, circumventing the difficulties of the ECG inverse problem, and may become an important a lternative to other ECG inverse solutions.