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 localization was obtained by calculating the three-dimensional current density distribution (3D-CDD) on the left ventricular surface. To estimate the accuracy of this localization technique, examinations of a healthy volunteer were additionally performed. The MCG-signals wererecorded in a magneticallyshielded roombya 49-channel magnetogradiometer. The corresponding morphologic information was recorded by magnetic resonance tomography(MRT). Thecoordinatesystems werematched with thehelp of markers. The3D-CDDwas calculated bythePhilips CURRY software package. The origin of a malignant VT determined by X-ray images of the ablation catheter position during the electrophysiological examination (EPE), was used as the gold standard. This was then compared with the localization results obtained by the 3D-CDD. It was found that the localization coordinates showed a difference of less than 10 mm.