Optical Coherence Tomography Imaging of the Purkinje Network

Optical imaging of the conduction system with fluorescent potentiometric probes has significantly advanced our undersigning of impulse initiation in the sino-atrial node,1 conduction through the atrioventricular node,2 and synchronization of contraction by the Purkinje system.3 However, further advancement of our understanding of molecular and cellular mechanisms of cardiac conduction is hampered by the limited experimental ability of existing imaging techniques to correlate functional and structural information in the complex three-dimensional structure of the conduction system of the heart. We suggest that the combination of fluorescent potentiometric imaging with optical coherence tomography (OCT) can potentially provide a unique opportunity for structurefunction studies at the cellular and tissue levels. In this study, we investigated the possibility of OCT imaging the threedimensional (3D) structure of the Purkinje network. The figure shows that OCT provides high-resolution 3D images of the complex morphology of the Purkinje network. OCT is a promising new tool for 3D structure-function imaging of the Purkinje network. OCT is an emerging non-invasive diagnostic technology that uses back-reflected infrared light (1,310 nm) to perform 3D imaging at micron-scale resolution.4 The technology is based on low-coherence Michelson interferometry. Light back-scattered from the sample interferes with reference light, allowing us to detect light reflected from a specific depth determined by the reference light path length. By scan-