Title :
Imaging of cardiac movement using ratiometric and nonratiometric optical mapping: effects of ischemia and 2, 3-butaneodione monoxime
Author :
Himel, Herman D., IV ; Knisley, Stephen B.
Author_Institution :
Dept. of Biomed. Eng. of the Sch. of Med., Univ. of North Carolina, Chapel Hill, NC, USA
Abstract :
Transmembrane voltage-sensitive fluorescent dyes are used to study electrical activity in hearts. Green and red fluorescence emissions from di-4-ANEPPS excited with 488 nm light indicate both transmembrane voltage changes and heart movement. We have previously shown that the ratio, green fluorescence divided by red fluorescence, indicates the transmembrane voltage without effects of movement. Here we examine the feasibility of measuring the movement, which is useful for the study of cardiac function, by subtracting this ratiometric signal from the red or green fluorescence signal. The results of this subtraction show tissue movement and its relative changes during cardiac ischemia and perfusion with an electromechanical uncoupling agent. By incorporating the spatial variations in fluorescence intensity from the heart, tissue movement can be qualitatively mapped to examine relative changes, however, with limited ability to quantify absolute displacement. Since these maps are obtained simultaneously with corresponding transmembrane potentials, the method allows study of spatiotemporal cardiac movement patterns and their relationship to the action potential.
Keywords :
bioelectric potentials; biological tissues; biomedical optical imaging; biomembranes; cardiology; dyes; fluorescence; haemorheology; 2, 3-butaneodione monoxime; action potential; cardiac ischemia; cardiac movement imaging; electrical activity; electromechanical uncoupling agent; green fluorescence emissions; heart; nonratiometric optical mapping; perfusion; ratiometric optical mapping; red fluorescence emissions; spatiotemporal cardiac movement patterns; tissue movement; transmembrane potentials; transmembrane voltage-sensitive fluorescent dyes; Biomedical optical imaging; Defibrillation; Fluorescence; Heart; Ischemic pain; Optical imaging; Optical recording; Optical sensors; Stimulated emission; Voltage; Electromechanical dissociation; fluorescence; tissue motion; transmembrane voltage-sensitive dye; Algorithms; Animals; Diacetyl; Feasibility Studies; Fluorescent Dyes; Heart Conduction System; Image Interpretation, Computer-Assisted; Microscopy, Fluorescence; Movement; Myocardial Contraction; Myocardial Ischemia; Rabbits; Spectrometry, Fluorescence; Ventricular Dysfunction, Left;
Journal_Title :
Medical Imaging, IEEE Transactions on
DOI :
10.1109/TMI.2005.861019