Early Denervation and Later Reinnervation of the Heart Following Cardiac Transplantation: A Review

H eart transplantation (HTx) surgically interrupts the parasympathetic vagal neurons and the intrinsic postganglionic sympathetic nerve fibers traveling from the stellate ganglia to the myocardium, causing axonal Wallerian degeneration and thus extrinsic cardiac denervation. Cardiac denervation causes loss of afferent nerves in the myocardium, which is hypothesized to impair the reflex responses of the sensory endings of the cardiopulmonary region. Cardiac denervation occurs in the context of a variable background of nerve density in the donor heart: it has been observed that nerve density differs greatly in all areas of the allograft. There was also a significant decrease in total nerve density in cardiac allografts after HTx.