Linked Life Data

15493508

Source:http://linkedlifedata.com/resource/pubmed/id/15493508

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2004-10-20
pubmed:abstractText
Major effects of stimulation on cardiac transmembrane potentials (Vm) are thought to occur under the electrode, however these have not been optically mapped due to blockage of light by electrodes. Here we optically mapped under translucent indium tin oxide (ITO) electrodes in hearts stained with transmembrane voltage sensitive fluorescent dye, di-4-ANEPPS excited at 488 nm. Emissions in wavelength bands 510-570 nm and >590 nm were similarly affected by changes in ITO transmittance due to electrochemical effects of current at the electrode interface. Dual-wavelength ratiometric mapping with the two emission bands revealed Vm under the electrode during plateau-phase stimulation (220 mA). Changes in Vm were heterogeneous under the electrode, and were anisotropic with larger values along the fiber axis. These results explain early excitation sites for sufficiently strong diastolic stimulation, and agree with theoretical predictions based on summation of anisotropic effects of point stimulation and a linear 3-d cardiac bidomain computer model. The bidomain model and experiments disagree under the edge of the electrode, where modeled Vm is much larger. Thus, changes in Vm under an electrode are anisotropic with greater Vm in the direction parallel to fibers. Nonlinear effects of stimulation in hearts may limit changes in Vm under the electrode edge.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0090-6964
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1202-10
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Cardiac optical mapping under a translucent stimulation electrode.
pubmed:affiliation
The Department of Biomedical Engineering of the School of Medicine, The University of North Carolina at Chapel Hill, NC 27599-7575, USA.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't, Evaluation Studies, Validation Studies