Iodine staining can grossly demonstrate the left ventricular peripheral conduction system in human hearts if performed shortly after death.
The peripheral conduction system was demonstrated grossly by iodine staining in a normal newborn heart and in one with a muscular ventricular septal defect. Staining of the conduction system was unsuccessful in a third heart when attempted over 2 hours after death. The left ventricular conduction system was easily visualized; however, the arborizations of conduction tissue over the right ventricular free wall endocardium were demonstrated poorly.
Spach et al. (Sun,) studied this question.