Stress testing in coronary artery disease by Magnetic Field Imaging: a 3D current distribution model.
OBJECTIVE
Magnetic field imaging (MFI) combines depolarization and repolarization registration of the cardiac electromagnetic field with a 3D current distribution model. An interesting application for MFI is the possibility to detect myocardial ischemia under stress.


METHODS
Using a new reconstruction technique, it is possible to generate a pseudo-current distribution on the epicardial surface: the comparison of the time evolution of such current distributions at rest and under stress shows difference in coronary artery disease (CAD). The model works with a realistic epicardial surface generate on the basis of computerised tomography or magnetic resonance tomography data or with a standardized ellipsoidal model. To take into account the vectorial character of the epicardial current distribution, the current flow in the epicardial surface element is represented in the graphic display by a cone. Thus indicating the direction of current flow the height of the cone represents the current intensity.


RESULTS
As an example of the method, data of pharmacological stress MFI on a CAD patient will be presented. The newly developed algorithm operates in different segments of the electromagnetic heart beat. The indicated myocardial area strongly correlated to invasive coronary angiography results. In such a situation the advantage provided by the "friendly" ellipsoidal surface on the numerical solution of the inverse problem seems to overcome the advantage of a realistic heart model.


CONCLUSIONS
We conclude MFI is a promising procedure for a non-invasive stress testing as well as screening method as for localization of myocardial ischemia.
Goernig
Matthias
M
Clinic of Internal Medicine I, University of Jena, Jena, Germany. matthias.goernig@med.uni-jena.de
De Melis
Massimo
M
Paolo
Dania Di Pietro
DD
Tedeschi
Walfred
W
Liehr
Mario
M
Figulla
Hans Reiner
HR
Erne
Sergio
S
D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D004574:Electromagnetic Fields; D005080:Exercise Test; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male