Abstract 12337: Non-invasive Localization of the Origin of Premature Ventricular Complex Using Novel Magnetocardiographic Approach

Abstract

Background: Multi-channel magnetocardiography (MCG) is a promising tool for evaluating cardiac activation with high spatial resolution, however, conventional measurement (from anterior chest wall alone) may not provide 3-dimentional information for assessing the whole heart activation. We aimed to localize the precise origin of premature ventricular complex (PVC) or ventricular tachycardia (VT) by our novel MCG approach where we repeated MCG recordings from anterior, posterior, and left lateral chest wall.

Methods: We recorded 64-Ch MCGs using a MCG system (MC-6400, Hitachi) simultaneously with a digitalized ECGs (II, V2, and V5) during PVC in 17 patients (men; 8, women; 9, age; 47±16) with PVC or VT. Measurements were repeated from 3 directions with sensors placed closed to anterior, posterior, and left lateral chest wall (in the supine, prone, and lateral positions, respectively) at a sampling interval of 1 ms. The distribution of current flow of 3-D maps during PVC was evaluated according to the origins (right ventricular outflow tract; RVOT anterior 8, posterior 1, free wall 2, septum 2,and left ventricular outflow tract; LVOT 4) determined by the successful catheter ablation procedure.

Results: The time delay from the onset of QRS to the instant of initial PVC signal arising on MCG was significantly greater in PVC from RVOT than from LVOT (36±6,vs. 15±11 ms, p<0.001). The cutoff value of>27 ms (RVOT) could correctly differentiate the both origins (RVOT 12/13, LVOT 4/4). Furthermore, PVC of each origin showed different MCG pattern according to the 4 anatomical RVOT regions and 2 LVOT regions (left coronary cusp; LCC, and right coronary cusp; RCC) as shown in Figure. The combination of the location of initial PVC signal and the current flow direction during mid to late QRS period could precisely differentiate the respective PVC origins of RVOT and LVOT.

Conclusion: 3-directional MCG approach can be a promising tool for localizing the origin of PVC accurately.