TY - JOUR
T1 - Extracting intramural wavefront orientation from optical upstroke shapes in whole hearts
AU - Zemlin, Christian W.
AU - Bernus, Olivier
AU - Matiukas, Arvydas
AU - Hyatt, Christopher J.
AU - Pertsov, Arkady M.
N1 - Funding Information:
Research in this article has been supported by National Institutes of Health grants 5P01HL039707, 5R01HL071635, and 5R01HL071762. O.B. is an honorary fellow of the Research Foundation, Flanders (FWO).
Funding Information:
The authors thank Rebecca Smith and Charles Danko for carefully reading the manuscript and Roman Zaritski for providing computational time on the Montclair cluster (National Science Foundation grant CTS-0319555).
PY - 2008/7/15
Y1 - 2008/7/15
N2 - Information about intramural propagation of electrical excitation is crucial to understanding arrhythmia mechanisms in thick ventricular muscle. There is currently a controversy over whether it is possible to extract such information from the shape of the upstroke in optical mapping recordings. We show that even in the complex geometry of a whole guinea pig heart, optical upstroke morphology reveals the 3D wavefront orientation near the surface. To characterize the upstroke morphology, we use VF*, the fractional level at which voltage-sensitive fluorescence, VF, has maximal time derivative. Low values of VF* (∼0.2) indicate a wavefront moving away from the surface, high values of VF* (∼0.6) a wavefront moving toward the surface, and intermediate values of VF* (∼0.4) a wavefront moving parallel to the surface. We further performed computer simulations using Luo-Rudy II electrophysiology and a simplified 3D geometry. The simulated VF* maps for free wall and apical stimulations as well as for sinus rhythm are in good quantitative agreement with the averaged experimental results. Furthermore, computer simulations show that the effect of the curvature of the heart on wave propagation is negligible.
AB - Information about intramural propagation of electrical excitation is crucial to understanding arrhythmia mechanisms in thick ventricular muscle. There is currently a controversy over whether it is possible to extract such information from the shape of the upstroke in optical mapping recordings. We show that even in the complex geometry of a whole guinea pig heart, optical upstroke morphology reveals the 3D wavefront orientation near the surface. To characterize the upstroke morphology, we use VF*, the fractional level at which voltage-sensitive fluorescence, VF, has maximal time derivative. Low values of VF* (∼0.2) indicate a wavefront moving away from the surface, high values of VF* (∼0.6) a wavefront moving toward the surface, and intermediate values of VF* (∼0.4) a wavefront moving parallel to the surface. We further performed computer simulations using Luo-Rudy II electrophysiology and a simplified 3D geometry. The simulated VF* maps for free wall and apical stimulations as well as for sinus rhythm are in good quantitative agreement with the averaged experimental results. Furthermore, computer simulations show that the effect of the curvature of the heart on wave propagation is negligible.
UR - http://www.scopus.com/inward/record.url?scp=47749128067&partnerID=8YFLogxK
U2 - 10.1529/biophysj.107.117887
DO - 10.1529/biophysj.107.117887
M3 - Article
C2 - 18390615
AN - SCOPUS:47749128067
SN - 0006-3495
VL - 95
SP - 942
EP - 950
JO - Biophysical Journal
JF - Biophysical Journal
IS - 2
ER -