Figure 1:
A. Anatomical location of human SAN. B. 3D SAN structure superimposed on CE-MRI, located along the crista terminalis (CT). C. Histology section with Masson’s trichrome staining shows the intramural location of the human SAN. D. Left, Masson’s trichrome staining shows human SAN fibrosis (blue). Middle, serial histology of SAN sections representing the transmural thickness of the SAN, stacked to generate computational 3D human SAN (Right). E. 3D computational structural analysis by fiber tracking approach displays microstructure of myofibers, fibrotic tissue, and fat in the human SAN complex (red) and surrounding atrial tissue (green). (Modified from1,12,5).