Calculation of optical signal using three-dimensional bidomain/diffusion model reveals distortion of the transmembrane potential. Biophys J 2008 Aug;95(4):2097-102
Date
05/20/2008Pubmed ID
18487289Pubmed Central ID
PMC2483762DOI
10.1529/biophysj.107.127852Scopus ID
2-s2.0-50349099106 (requires institutional sign-in at Scopus site) 9 CitationsAbstract
Optical mapping experiments allow investigators to view the effects of electrical currents on the transmembrane potential, V(m), as a shock is applied to the heart. One important consideration is whether the optical signal accurately represents V(m). We have combined the bidomain equations along with the photon diffusion equation to study the excitation and emission of photons during optical mapping of cardiac tissue. Our results show that this bidomain/diffusion model predicts an optical signal that is much smaller than V(m) near a stimulating electrode, a result consistent with experimental observations. Yet, this model, which incorporates the effect of lateral averaging, also reveals an optical signal that overestimates V(m) at distances >1 mm away from the electrode. Although V(m) falls off with distance r from the electrode as exp(-r/lambda)/r, the optical signal decays as a simple exponential, exp(-r/lambda). Moreover, regions of hyperpolarization adjacent to a cathode are emphasized in the optical signal compared to the region of depolarization under the cathode. Imaging methods utilizing optical mapping techniques will need to account for these distortions to accurately reconstruct V(m).
Author List
Prior P, Roth BJAuthor
Phillip Prior PhD Assistant Professor in the Radiation Oncology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Cell MembraneComputer Simulation
Diagnostic Imaging
Image Interpretation, Computer-Assisted
Imaging, Three-Dimensional
Membrane Potentials
Models, Biological
Optics and Photonics
