History of Optical Mapping

Optical mapping is an imaging technique that is used to record physiologic phenomena from live tissue. To date, optical imaging has been applied in the heart to record NADH+, transmembrane potential, and intracellular calcium transients. While NADH+ imaging relies on the intrinsic fluorescent signals from the tissue, fluorescent dyes have been developed to record transmembrane potential and calcium transients. Optical mapping has been applied to cardiac tissue at multiple scales, from single cells all the way up to in vivo whole hearts. This technique has also evolved in terms of number heart surfaces and number of parameters that can be measured simultaneously from the heart. The latter technique gives the user the ability to look at the inter-relationship between different physiological phenomena. This chapter discusses the origins of the use of optical mapping in cardiac research, the process of optical mapping of the heart, and the evolution of dyes and equipment used.