title: Towards Depth-Resolved Optical Imaging of Cardiac Electrical Activity.
abstract: The spatiotemporal dynamics of arrhythmias are likely to be complex three-dimensional phenomena. Yet, the lack of high-resolution three-dimensional imaging techniques, both in the clinic and the experimental lab, limits our ability to better understand the mechanisms of such arrhythmias. Optical mapping using voltage-sensitive dyes is a widely used tool in experimental electrophysiology. It has been known for decades that even in its most basic application, epi-fluorescence, the optical signal contains information from within a certain intramural volume. Understanding of this fundamental property of optical signals has paved the way towards novel three-dimensional optical imaging techniques. Here, we review our current understanding of the three-dimensional nature of optical signals; how penetration depths of cardiac optical imaging can be improved by using novel imaging modalities and finally, we highlight new techniques inspired from optical tomography and aiming at full depth-resolved optical mapping of cardiac electrical activity.
authors.affiliation: L'Institut de rythmologie et modélisation cardiaque LIRYC, Centre de Recherche Cardiothoracique de Bordeaux, Université de Bordeaux, Inserm U1045, Pessac, France, Richard.walton@ihu-liryc.fr.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Walton
authors.forename: Olivier
authors.initials: O
authors.lastname: Bernus
mesh_terms: D000200:Action Potentials; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology; D005456:Fluorescent Dyes; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D009206:Myocardium / Q000473:pathology; D041622:Tomography, Optical / Q000295:instrumentation / Q000379:methods; D056969:Voltage-Sensitive Dye Imaging / Q000295:instrumentation / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes