Current-density estimation of exercise-induced ischemia in patients with multivessel coronary artery disease.
Magnetocardiographic and body surface potential mapping data measured in 6 patients with multivessel coronary artery disease were used in equivalent current-density estimation (CDE). Patient-specific boundary-element torso models were acquired from magnetic resonance images. Positron emission tomography data registrated with anatomical magnetic resonance imaging data provided the gold standard. Discrete current-density estimation values were computed on the epicardial surface of the left ventricle from difference (stress-rest) ST-segment maps. The ill-posed inverse problem was regularized with 3 different methods (Tikhonov regularization with an identity or a surface Laplacian operator and a maximum a posteriori estimator). Comparisons with positron emission tomography studies showed that the maximum a posteriori estimator is superior to other regularizations, provided that a suitable a priori information is available. In general, good correspondence was found for segments of high and low amplitude in current-density estimations, and the viable and scar areas in positron emission tomography, respectively.
Nenonen
J
J
Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo, Finland. Jukka.Nenonen@hut.fi
Pesola
K
K
Hänninen
H
H
Lauerma
K
K
Takala
P
P
Mäkelä
T
T
Mäkijärvi
M
M
Knuuti
J
J
Toivonen
L
L
Katila
T
T
D018780:Body Surface Potential Mapping; D003327:Coronary Disease / Q000175:diagnosis / Q000503:physiopathology*; D004562:Electrocardiography; D015444:Exercise; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology; D014055:Tomography, Emission-Computed