Localization of a ventricular tachycardia-focus with multichannel magnetocardiography and three-dimensional current density reconstruction

The objective of this case report is to determine the accurate localization of a malignant ventricular tachycardia (VT)focus by combining multichannel magnetocardiographic (MCG) information with morphologic data. The localiza tion was obtained by calculating the three-dimensional current density dist ribution (3D-CDD) on the left ventricular surface. To estimate the accuracy of this localization technique, examinations of a healthy volunteer were a dditionally performed. The MCG-signals were recorded in a magnetically shie lded room by a 49-channel magnetogradiometer. The corresponding morphologic information was recorded by magnetic resonance tomography (MRT). The coord inate systems were matched with the help of markers. The 3D-CDD was calcula ted by the Philips CURRY software package. The origin of a malignant VT det ermined by X-ray images of the ablation catheter position during the electr ophysiological examination (EPE) was used as the gold standard. This was th en compared with the localization results obtained by the 3D-CDD. It was fo und that the localization coordinates showed a difference of less than 10 m m.