Figure 1

(A) A composite view of the anterior thorax and heart shows the contrast between the helical pattern of the fibers in the myocardium (color-coded by HA) and the linear organization of skeletal muscle fibers in the chest wall. (B) The fiber architecture of the RV can be well resolved in vivo and lacks the circumferential fibers seen in the LV (C). (D) Tractography within a slab located at the basal-level depicting the transmural myofiber arrangement of both RV and LV. The intertwined arrangement of myofibers at the anteroseptal RV-LV junction is slightly magnified.