Fig. 3.

Identification of the crista terminalis and interatrial septum with OCT. (a) Photograph of an SA nodal preparation as viewed from the endocardium with the OCT fields of view for the CT and IAS identified by the green and blue boxes, respectively. OCT images of the unidirectional fiber orientation of the CT and IAS 0.17 mm (b and d) and 0.49 mm (c and e) below the endocardium. Abbreviations: SVC, superior vena cava; IVC, inferior vena cava; RAA, right atrial appendage; CT, crista terminalis; IAS, interatrial septum.