Optical Mapping of the Cardiac Electrical Activity

The method of optical mapping of the cardiac electrical activity using potential-sensitive dyes became popular during last decade. One of main reasons of rapid development of the method was inability of ordinary intra and extracellular techniques to provide mapping of electrical activity of the heart with high spatial-temporal resolution. Despite long period of development of these procedures they turned out to be inapplicable in at least two key fields of research: studies of the role of spatial-temporal organization of repolarization in arrhythmogenesis and investigation of effects of external electrical field on cellular electrical activity. Optical registration of transmembrane potentials can be applied both at subcellular level and at the level of the heart as a whole. Response time of rapid potentials of sensitive dyes lies within microseconds. Thus resolution of optical registration exceeds that of microelectrode techniques. Rapid progress of computer technologies promoted registration of optical potentials simultaneously from many sites of the heart. The latter allows to obtain maps of electrical activity with high temporal and spatial resolution. Modern technical approaches to creation of optical systems for visualization of fluorescent signals as well as novel system of optical mapping of the heart designed in the Cleveland Clinic are also presented in this review.