Noninvasive localization of premature ventricular activity using different equivalent point sources

Comparison of the localization error of inverse estimation of the origin of premature ventricular contraction using three different formulations of transfer matrix between the equivalent source and the surface potentials was performed in this study. Body surface potential maps measured in 63 precordial leads during nine spontaneous PVCs in one patient provided by Karlsruhe Institute of Technology in EDGAR database were used as input data. The localization error was evaluated with respect to two reference points PVC1 and PVC2 assigned during the ablation procedure. The transfer matrices for epicardial potentials, transmembrane voltages and dipoles situated on the joined endo-and-epicardial surface were used for inverse computation searching the best single point generator representing the input data For all nine considered PVCs the locations of the inverse results were very stable - for particular transfer matrix they resulted in the same point or in adjoining points for all cases. Mean localization error with respect to PVC1 or PVC2 was from 21.3 to 26.2 mm and from 15.0 to 26.4 mm respectively. The results obtained by inverse solution supposing single point source were similar regardless of the source formulation.