The three-dimensional cardiac electrical imaging (3DCEI) technique was previously developed to estimate the initiation site(s) of cardiac activation and activation sequence from the noninvasively measured body surface potential maps (BSPMs). The aim of this study was to develop and evaluate the capability of 3DCEI in mapping the transmural distribution of extracellular potentials and localizing initiation sites of ventricular activation in an in vivo animal model. A control swine model (n = 10) was employed in this study. The heart-torso volume conductor model and the excitable heart model were constructed based on each animal's preoperative MR images and a priori known physiological knowledge. Body surface potential mapping and intracavitary noncontact mapping (NCM) were simultaneously conducted during acute ventricular pacing. The 3DCEI analysis was then applied on the recorded BSPMs. The estimated initiation sites were compared to the precise pacing sites; as a subset of the mapped transmural potentials by 3DCEI, the electrograms on the left ventricular endocardium were compared to the corresponding output of the NCM system. Over the 16 LV and 48 RV pacing studies, the averaged localization error was 6.1 ± 2.3 mm, and the averaged correlation coefficient between the estimated endocardial electrograms by 3DCEI and from the NCM system was 0.62 ± 0.09. The results demonstrate that the 3DCEI approach can well localize the sites of initiation of ectopic beats and can obtain physiologically reasonable transmural potentials in an in vivo setting during focal ectopic beats. This study suggests the feasibility of tomographicmapping of 3D ventricular electrograms from the body surface recordings.
Bibliographical noteFunding Information:
Manuscript received April 19, 2012; revised May 24, 2012. First published June 6, 2012. Date of publication June 06, 2012; date of current version August 28, 2012. This work was supported in part by the National Institutes of Health under Grant NIH R01HL080093, in part by the National Science Foundation under Grant NSF CBET-0756331, and in part by a grant from the Institute of Engineering in Medicine of the University of Minnesota. The work of C. Liu was supported by a Doctoral Dissertation Fellowship from the Graduate School of the University of Minnesota. Asterisk indicates corresponding author.
- Body surface potential mapping
- Noncontact mapping
- Three-dimensional (3D) cardiac electrical imaging
- Transmural potential