Magnetocardiographic functional localization using a current dipole in a realistic torso.

We describe a fast and numerically effective biomagnetic inverse solution using a moving dipole in a realistic homogeneous torso. We applied the localization model and high-resolution magnetocardiographic mapping to localize noninvasively the ventricular preexcitation site in ten patients suffering from Wolff-Parkinson-White syndrome. In all cases, the computed localization results were compared to the results obtained by invasive catheter technique. Using a standard-size torso model in all cases, the average 3-D distance between the computed noninvasive locations and the invasively obtained results was 2.8 +/- 1.4 cm. When the torso was rescaled to better match the true shape of the subject in five cases, the 3-D average was improved to 2.2 +/- 1.0 cm. This accuracy is very satisfactory, suggesting that the method would be clinically useful.