We have developed a new approach for imaging cardiac transmembrane potentials (TMPs) within the three-dimensional (3-D) myocardium by means of an anisotropic heart model. The cardiac TMP distribution is estimated from body surface electrocardiograms by minimizing objective functions of the "measured" body surface potential maps (BSPMs) and the heart-model-generated BSPMs. Computer simulation studies have been conducted to evaluate the present 3-D TMP imaging approach using pacing protocols. Simulations of single-site pacing at 24 sites throughout the ventricles, as well as dual-site pacing at 12 pairs of sites in the vicinity of atrio-ventricular ring were performed. The present simulation results show that the correlation coefficient (CC) and relative error (RE) between the "true" and inversely estimated TMP distributions were 0.9915 ± 0.0041 and 0.1266 ± 0.0326, for single-site pacing, and 0.9889 ± 0.0034 and 0.1473 ± 0.0237 for dual-site pacing, respectively, when 10 μV Gaussian white noise (GWN) was added to the BSPMs. The effects of heart and torso geometry uncertainty were also evaluated by shifting the heart position by 10 mm and altering the torso size by 10%. The CC between the "true" and inversely estimated TMP distributions was above 0.97 when these geometry uncertainties were considered. The present simulation results demonstrate the feasibility of noninvasive estimation of TMP distribution throughout the ventricles from body surface electrocardiographic measurements, and suggest that the present method may become a useful alternative in noninvasive imaging of distributed cardiac electrophysiological processes within the 3-D myocardium.
Bibliographical noteFunding Information:
Manuscript received September 6, 2002; revised March 10, 2003. This work was supported in part by the National Science Foundation (NSF) under Grant BES-0201939 and CAREER Award BES-9875344, in part by the American Heart Association under Grant 0140132N, and in part by the National Institutes of Health (NIH) under Grant 1R01EB178. Asterisk indicates corresponding author. *B. He is with the University of Illinois at Chicago, SEO 218, M/C-063, 851 S. Morgan Street, Chicago, IL 60607 USA (e-mail: email@example.com).
- Body surface potential map
- Cardiac activation
- Cardiac mapping
- Electrocardiographic imaging
- Electrocardiographic inverse problem
- Transmembrane potential imaging