Cardiac source localization by means of a single moving dipole solution during endocardial pacing in an animal model.

The accuracy of localizing the initiation site of cardiac activation by noninvasively estimating a single moving dipole (SMD) was investigated in a swine model. Body surface potential mapping (BSPM) and intracavitary noncontact mapping (NCM) were performed simultaneously during acute left ventricular (LV) endocardial pacing. For each animal, the boundary element model was constructed from preoperative magnetic resonance images (MRI). In each pacing study, the initiation site was localized by inversely estimating the location of an SMD from BSPM data. The results were compared with the precise pacing sites recorded by the NCM system. In total, four pacing sites from two pigs were analyzed, and the averaged source localization error was 16.8 +/- 2.3 mm. The present results indicate the potential of localizing focal cardiac events by estimating single moving dipole.